From 288bb8511f89741af1fd36605af397dd57e116c8 Mon Sep 17 00:00:00 2001
From: HailSanta <53960937+HailSanta@users.noreply.github.com>
Date: Fri, 3 Mar 2023 22:20:43 -0500
Subject: [PATCH] world kooper cleanup (#963)

* kooper cleanup

* second pass

---------

Co-authored-by: HailSanta <Hail2Santa@gmail.com>
---
 include/common_structs.h                      |   2 +-
 include/dead.h                                |   2 +-
 include/enums.h                               |  16 +-
 include/npc.h                                 |  20 +-
 src/23680.c                                   |   2 +-
 src/38F00.c                                   |   2 +-
 src/39210_len_aa0.c                           |   8 +-
 src/C50A0.c                                   |  77 +-
 src/a5dd0_len_114e0.c                         |  10 +-
 src/entity/jan_iwa/Plants1.c                  |   2 +-
 src/evt/npc_api.c                             |   6 +-
 src/evt/player_api.c                          |   2 +-
 src/npc.c                                     | 203 ++--
 src/world/area_dgb/dgb_01/dgb_01_5_npc.c      |   8 +-
 src/world/area_kmr/kmr_02/kmr_02_3_npc.c      |   2 +-
 src/world/common/enemy/ai/AvoidPlayerAI.inc.c |   4 +-
 src/world/common/enemy/ai/CleftAI.inc.c       |   2 +-
 src/world/common/enemy/ai/GuardAI.inc.c       |   2 +-
 src/world/common/enemy/ai/MontyMoleAI.inc.c   |   2 +-
 .../common/enemy/ai/States_PatrolAI.inc.c     |   6 +-
 .../common/todo/AwaitPlayerNearNpc.inc.c      |   2 +-
 .../common/todo/CheckPartnerFlags1000.inc.c   |   2 +-
 src/world/partner/bombette.c                  |  16 +-
 src/world/partner/bow.c                       |   2 +-
 src/world/partner/goombario.c                 |   4 +-
 src/world/partner/kooper.c                    | 897 +++++++++---------
 src/world/partner/kooper.h                    |   8 +-
 src/world/partner/lakilester.c                |   4 +-
 src/world/partner/parakarry.c                 |   4 +-
 src/world/partner/watt.c                      |   4 +-
 src/world/partners.c                          |  77 +-
 src/world/partners.h                          |   2 +-
 tools/ignored_funcs.txt                       |   2 +-
 tools/splat_ext/pm_charset.py                 |  28 +-
 ver/us/symbol_addrs.txt                       |  62 +-
 ver/us/undefined_syms.txt                     |   2 +-
 36 files changed, 775 insertions(+), 719 deletions(-)

diff --git a/include/common_structs.h b/include/common_structs.h
index 77a9a15106..3ce99fbf12 100644
--- a/include/common_structs.h
+++ b/include/common_structs.h
@@ -1514,7 +1514,7 @@ typedef struct ItemEntityPhysicsData {
     /* 0x10 */ f32 velx;
     /* 0x14 */ f32 velz;
     /* 0x18 */ f32 moveAngle;
-    /* 0x1C */ s32 unk_1C;
+    /* 0x1C */ s32 timeLeft;
     /* 0x20 */ s32 unk_20;
 } ItemEntityPhysicsData; // size = 0x24
 
diff --git a/include/dead.h b/include/dead.h
index 6872fefa05..f67599dd17 100644
--- a/include/dead.h
+++ b/include/dead.h
@@ -71,7 +71,7 @@
 #define sfx_play_sound_with_params dead_sfx_play_sound_with_params
 #define sfx_get_spatialized_sound_params dead_sfx_get_spatialized_sound_params
 #define npc_test_move_simple_without_slipping dead_npc_test_move_simple_without_slipping
-#define func_8003D660 dead_func_8003D660
+#define spawn_surface_effects dead_spawn_surface_effects
 #define get_item_entity dead_get_item_entity
 #define gOverrideFlags dead_gOverrideFlags
 #define set_message_msg dead_set_message_msg
diff --git a/include/enums.h b/include/enums.h
index 5b7ec67fb7..d0129d7fa4 100644
--- a/include/enums.h
+++ b/include/enums.h
@@ -3245,7 +3245,7 @@ enum ItemEntityFlags {
     ITEM_ENTITY_FLAG_10            = 0x00000010,
     ITEM_ENTITY_FLAG_HIDDEN        = 0x00000040, // do not render; player cant pickup
     ITEM_ENTITY_FLAG_80            = 0x00000080,
-    ITEM_ENTITY_FLAG_100           = 0x00000100,
+    ITEM_ENTITY_FLAG_AUTO_COLLECT  = 0x00000100,
     ITEM_ENTITY_FLAG_NEVER_VANISH  = 0x00000200,
     ITEM_ENTITY_FLAG_400           = 0x00000400,
     ITEM_ENTITY_FLAG_800           = 0x00000800,
@@ -3258,7 +3258,7 @@ enum ItemEntityFlags {
     ITEM_ENTITY_FLAG_40000         = 0x00040000,
     ITEM_ENTITY_FLAG_TRANSPARENT   = 0x00080000,
     ITEM_ENTITY_FLAG_100000        = 0x00100000,
-    ITEM_ENTITY_FLAG_200000        = 0x00200000,
+    ITEM_ENTITY_FLAG_CANT_COLLECT  = 0x00200000,
     ITEM_ENTITY_FLAG_400000        = 0x00400000,
     ITEM_ENTITY_FLAG_800000        = 0x00800000,
     ITEM_ENTITY_FLAG_1000000       = 0x01000000,
@@ -3415,8 +3415,8 @@ enum EventSupressFlags {
 enum PartnerActions {
     PARTNER_ACTION_NONE             = 0, // generic state
     PARTNER_ACTION_USE              = 1, // generic state
-    PARTNER_ACTION_KOOPER_1         = 1,
-    PARTNER_ACTION_KOOPER_2         = 2,
+    PARTNER_ACTION_KOOPER_GATHER    = 1,
+    PARTNER_ACTION_KOOPER_TOSS      = 2,
     PARTNER_ACTION_BOMBETTE_1       = 1,
     PARTNER_ACTION_BOMBETTE_2       = 2,
     PARTNER_ACTION_BOMBETTE_3       = 3,
@@ -3491,7 +3491,7 @@ enum NpcFlags {
     NPC_FLAG_GRAVITY                        = 0x00000200, // Enables gravity. Does nothing if NPC_FLAG_JUMPING is set.
     NPC_FLAG_DONT_UPDATE_SHADOW_Y           = 0x00000400, // When shadow raycasting is off, only X and Z update as NPC moves
     NPC_FLAG_JUMPING                        = 0x00000800,
-    NPC_FLAG_FALLING                        = 0x00001000,
+    NPC_FLAG_GROUNDED                       = 0x00001000, // Touching the ground
     NPC_FLAG_COLLDING_WITH_WORLD            = 0x00002000, // Colliding with world in front or to the sides of the NPC
     NPC_FLAG_COLLDING_FORWARD_WITH_WORLD    = 0x00004000, // Colliding with world directly in front of NPC
     NPC_FLAG_IGNORE_ENTITY_COLLISION        = 0x00008000,
@@ -5248,6 +5248,12 @@ enum SurfaceType {
     */
 };
 
+typedef enum SurfaceInteractMode {
+    SURFACE_INTERACT_WALK       = 0,
+    SURFACE_INTERACT_RUN        = 1,
+    SURFACE_INTERACT_LAND       = 2,
+} SurfaceInteractMode;
+
 //TODO -- temporarily combined with SurfaceType for map data dumper
 enum ColliderFlags {
     COLLIDER_FLAGS_UPPER_MASK        = 0x7FFFFE00, // map data dumper needs this to be first
diff --git a/include/npc.h b/include/npc.h
index 8d19c821e0..ce739d47be 100644
--- a/include/npc.h
+++ b/include/npc.h
@@ -461,9 +461,9 @@ void npc_do_other_npc_collision(Npc* npc);
 /// @returns TRUE if a collision occurred
 s32 npc_do_player_collision(Npc* npc);
 
-void npc_do_gravity(Npc* npc);
+void npc_try_apply_gravity(Npc* npc);
 
-s32 func_800397E8(Npc* npc, f32 velocity);
+s32 npc_try_snap_to_ground(Npc* npc, f32 velocity);
 
 /// Updates all NPCs.
 void update_npcs(void);
@@ -528,7 +528,7 @@ void npc_remove_decoration(Npc* npc, s32 idx);
 
 s32 npc_update_decorations(Npc* npc);
 
-void npc__remove_decoration(Npc* npc, s32 idx);
+void npc_remove_decoration_impl(Npc* npc, s32 idx);
 
 void npc_reset_current_decoration(Npc* npc, s32 idx);
 
@@ -596,19 +596,19 @@ void func_8003D3BC(Npc* npc);
 
 void func_8003D624(Npc* npc, s32 arg1, s32 arg2, s32 arg3, s32 arg4, s32 arg5, s32 arg6);
 
-void func_8003D660(Npc* npc, s32);
+void spawn_surface_effects(Npc* npc, SurfaceInteractMode mode);
 
-void func_8003D788(Npc* npc, s32);
+void spawn_default_surface_effects(Npc* npc, SurfaceInteractMode mode);
 
-void func_8003DA38(Npc* npc, s32);
+void spawn_flower_surface_effects(Npc* npc, SurfaceInteractMode mode);
 
-void func_8003DC38(Npc* npc, s32);
+void spawn_cloud_surface_effects(Npc* npc, SurfaceInteractMode mode);
 
-void func_8003DFA0(Npc* npc, s32);
+void spawn_snow_surface_effects(Npc* npc, SurfaceInteractMode mode);
 
-void func_8003E0D4(Npc* npc, s32);
+void spawn_hedge_surface_effects(Npc* npc, SurfaceInteractMode mode);
 
-void func_8003E1D0(Npc* npc, s32);
+void spawn_water_surface_effects(Npc* npc, SurfaceInteractMode mode);
 
 /// Duplicate of set_defeated().
 void COPY_set_defeated(s32 mapID, s32 encounterID);
diff --git a/src/23680.c b/src/23680.c
index ace796be18..42a121929f 100644
--- a/src/23680.c
+++ b/src/23680.c
@@ -815,7 +815,7 @@ void basic_ai_chase(Evt* script, MobileAISettings* aiSettings, EnemyDetectVolume
         }
     }
 
-    func_8003D660(npc, 1);
+    spawn_surface_effects(npc, SURFACE_INTERACT_RUN);
     npc_move_heading(npc, npc->moveSpeed, npc->yaw);
 
     if (npc->moveSpeed > 8.0 && !(gGameStatusPtr->frameCounter % 5)) {
diff --git a/src/38F00.c b/src/38F00.c
index 0cac9c59cf..1384900777 100644
--- a/src/38F00.c
+++ b/src/38F00.c
@@ -158,7 +158,7 @@ ApiStatus func_8005DD54(Evt* script, s32 isInitialCall) {
 }
 
 ApiStatus func_8005DDF0(Evt* script, s32 isInitialCall) {
-    if (~gCurrentEncounter.unk_08) {
+    if (gCurrentEncounter.unk_08 != -1) {
         return ApiStatus_DONE1;
     } else {
         return ApiStatus_BLOCK;
diff --git a/src/39210_len_aa0.c b/src/39210_len_aa0.c
index 3310934cd0..d266e7aacf 100644
--- a/src/39210_len_aa0.c
+++ b/src/39210_len_aa0.c
@@ -130,7 +130,7 @@ void npc_follow_npc(Npc* npc) {
             }
 
             npc->currentAnim = followData->anims->run;
-            if (!(npc->flags & NPC_FLAG_FALLING)) {
+            if (!(npc->flags & NPC_FLAG_GROUNDED)) {
                 npc->currentAnim = followData->anims->fall;
             }
 
@@ -177,7 +177,7 @@ void npc_follow_npc(Npc* npc) {
                 historyPoint = &followData->moveHistory[followData->targetPointIdx];
                 targetX = historyPoint->pos.x;
                 targetZ = historyPoint->pos.z;
-                if (npc->flags & NPC_FLAG_FALLING) {
+                if (npc->flags & NPC_FLAG_GROUNDED) {
                     if (historyPoint->isAirborne) {
                         followData->followState = NPC_FOLLOW_STATE_JUMP;
                         break;
@@ -185,12 +185,12 @@ void npc_follow_npc(Npc* npc) {
                 }
             }
 
-            if (!(npc->flags & NPC_FLAG_FALLING)) {
+            if (!(npc->flags & NPC_FLAG_GROUNDED)) {
                 npc->moveSpeed *= 0.5f;
             }
             npc->yaw = yaw;
             npc_move_heading(npc, npc->moveSpeed, yaw);
-            if ((npc->flags & NPC_FLAG_COLLDING_FORWARD_WITH_WORLD) && (npc->flags & NPC_FLAG_FALLING)) {
+            if ((npc->flags & NPC_FLAG_COLLDING_FORWARD_WITH_WORLD) && (npc->flags & NPC_FLAG_GROUNDED)) {
                 followData->followState = NPC_FOLLOW_STATE_JUMP;
             }
             break;
diff --git a/src/C50A0.c b/src/C50A0.c
index f2c73de8e1..ba131ace5f 100644
--- a/src/C50A0.c
+++ b/src/C50A0.c
@@ -1797,8 +1797,8 @@ s32 test_item_player_collision(ItemEntity* item) {
 
     actionState = playerStatus->actionState;
 
-    if (item->flags & ITEM_ENTITY_FLAG_100) {
-        item->flags &= ~ITEM_ENTITY_FLAG_100;
+    if (item->flags & ITEM_ENTITY_FLAG_AUTO_COLLECT) {
+        item->flags &= ~ITEM_ENTITY_FLAG_AUTO_COLLECT;
         return TRUE;
     }
 
@@ -1810,7 +1810,7 @@ s32 test_item_player_collision(ItemEntity* item) {
         return FALSE;
     }
 
-    if (item->flags & ITEM_ENTITY_FLAG_200000) {
+    if (item->flags & ITEM_ENTITY_FLAG_CANT_COLLECT) {
         return FALSE;
     }
 
@@ -1949,7 +1949,7 @@ s32 test_item_entity_position(f32 x, f32 y, f32 z, f32 dist) {
             continue;
         }
 
-        if (item->flags & ITEM_ENTITY_FLAG_200000) {
+        if (item->flags & ITEM_ENTITY_FLAG_CANT_COLLECT) {
             continue;
         }
 
@@ -1967,7 +1967,7 @@ void set_item_entity_flags(s32 index, s32 flags) {
     ItemEntity* itemEntity = gCurrentItemEntities[index];
 
     itemEntity->flags |= flags;
-    if (itemEntity->flags & ITEM_ENTITY_FLAG_200000) {
+    if (itemEntity->flags & ITEM_ENTITY_FLAG_CANT_COLLECT) {
         D_801565A8 = 1;
     }
 }
@@ -1978,10 +1978,10 @@ void clear_item_entity_flags(s32 index, s32 flags) {
     itemEntity->flags &= ~flags;
 }
 
-void func_801341B0(s32 index) {
+void auto_collect_item_entity(s32 index) {
     ItemEntity* itemEntity = gCurrentItemEntities[index];
     gOverrideFlags |= GLOBAL_OVERRIDES_40;
-    itemEntity->flags |= ITEM_ENTITY_FLAG_100;
+    itemEntity->flags |= ITEM_ENTITY_FLAG_AUTO_COLLECT;
 }
 
 /// @returns TRUE when "you got X" popup is on-screen
@@ -2144,22 +2144,22 @@ void update_item_entity_collectable(ItemEntity* item) {
                 }
 
                 if (item->spawnType != ITEM_SPAWN_MODE_TOSS_FADE1) {
-                    physData->unk_1C = 180;
-                    physData->unk_20 = 0;
+                    physData->timeLeft = 180;
+                    physData->unk_20 = FALSE;
                 } else {
                     if (!(item->flags & ITEM_ENTITY_FLAG_400000)) {
-                        physData->unk_1C = 0x11;
+                        physData->timeLeft = 17;
                     } else {
-                        physData->unk_1C = 0x14;
+                        physData->timeLeft = 20;
                     }
-                    physData->unk_20 = 0;
+                    physData->unk_20 = FALSE;
                     physData->verticalVelocity = 15.0f;
                     physData->gravity = 1.6f;
                 }
 
                 if (item->spawnType == ITEM_SPAWN_MODE_ITEM_BLOCK_SPAWN_ALWAYS) {
-                    physData->unk_1C = 60;
-                    physData->unk_20 = 0;
+                    physData->timeLeft = 60;
+                    physData->unk_20 = FALSE;
                     physData->velx = 0.0f;
                     physData->velz = 0.0f;
                 }
@@ -2168,14 +2168,14 @@ void update_item_entity_collectable(ItemEntity* item) {
                     physData->verticalVelocity = 0.0f;
                     physData->velx = 0.0f;
                     physData->velz = 0.0f;
-                    physData->unk_20 = 1;
+                    physData->unk_20 = TRUE;
                 }
 
                 if (item->spawnType == ITEM_SPAWN_MODE_FIXED_SPAWN_ALWAYS) {
                     physData->verticalVelocity = 0.0f;
                     physData->velx = 0.0f;
                     physData->velz = 0.0f;
-                    physData->unk_20 = 1;
+                    physData->unk_20 = TRUE;
                 }
 
                 if (item->flags & ITEM_ENTITY_FLAG_800) {
@@ -2185,29 +2185,28 @@ void update_item_entity_collectable(ItemEntity* item) {
                 break;
             case 1:
                 physData = item->physicsData;
-                if (item->spawnType != ITEM_SPAWN_MODE_ITEM_BLOCK_SPAWN_ALWAYS &&
-                    item->spawnType != ITEM_SPAWN_MODE_TOSS_FADE1 &&
-                    physData->unk_20 != 0 &&
-                    test_item_player_collision(item))
-                {
+                if (item->spawnType != ITEM_SPAWN_MODE_ITEM_BLOCK_SPAWN_ALWAYS
+                    && item->spawnType != ITEM_SPAWN_MODE_TOSS_FADE1
+                    && physData->unk_20
+                    && test_item_player_collision(item)
+                ) {
                     item->state = 3;
                     break;
                 }
 
-                if (!(item->flags & ITEM_ENTITY_FLAG_NEVER_VANISH)) {
-                    if (!(gOverrideFlags & (GLOBAL_OVERRIDES_200 | GLOBAL_OVERRIDES_DISABLE_BATTLES))) {
-                        if (!(item->flags & ITEM_ENTITY_FLAG_200000)) {
-                            physData->unk_1C--;
-                            if (physData->unk_1C < 0) {
-                                item->state = 2;
-                                break;
-                            }
-                        }
+                if (!(item->flags & ITEM_ENTITY_FLAG_NEVER_VANISH)
+                   && !(gOverrideFlags & (GLOBAL_OVERRIDES_200 | GLOBAL_OVERRIDES_DISABLE_BATTLES))
+                   && !(item->flags & ITEM_ENTITY_FLAG_CANT_COLLECT)
+                ) {
+                    physData->timeLeft--;
+                    if (physData->timeLeft < 0) {
+                        item->state = 2;
+                        break;
                     }
                 }
 
                 if (!(item->flags & ITEM_ENTITY_FLAG_FIXED)) {
-                    if (!(item->flags & ITEM_ENTITY_FLAG_200000)) {
+                    if (!(item->flags & ITEM_ENTITY_FLAG_CANT_COLLECT)) {
                         physData->verticalVelocity -= physData->gravity;
                         if (physData->verticalVelocity < -16.0) {
                             physData->verticalVelocity = -16.0f;
@@ -2236,7 +2235,7 @@ void update_item_entity_collectable(ItemEntity* item) {
                     outZ = item->position.z;
                     outDepth = temp + physData->verticalVelocity;
 
-                    if (physData->unk_20 == 0) {
+                    if (!physData->unk_20) {
                         hit = npc_raycast_up(COLLISION_CHANNEL_20000, &outX, &outY, &outZ, &outDepth);
                     } else {
                         hit = npc_raycast_up(COLLISION_CHANNEL_20000, &outX, &outY, &outZ, &outDepth);
@@ -2257,7 +2256,7 @@ void update_item_entity_collectable(ItemEntity* item) {
                     outY = item->position.y;
                     outZ = item->position.z;
 
-                    if (physData->unk_20 == 0) {
+                    if (!physData->unk_20) {
                         hit = npc_test_move_complex_with_slipping(COLLISION_CHANNEL_20000, &outX, &outY, &outZ, 0.0f, physData->moveAngle, physData->constVelocity, physData->unk_08);
                     } else {
                         hit = npc_test_move_simple_with_slipping(COLLISION_CHANNEL_20000, &outX, &outY, &outZ, 0.0f, physData->moveAngle, physData->constVelocity, physData->unk_08);
@@ -2280,13 +2279,13 @@ void update_item_entity_collectable(ItemEntity* item) {
                     item->spawnType != ITEM_SPAWN_MODE_ITEM_BLOCK_SPAWN_ALWAYS &&
                     physData->verticalVelocity <= 0.0)
                 {
-                    physData->unk_20 = 1;
+                    physData->unk_20 = TRUE;
                     if (item->spawnType != ITEM_SPAWN_MODE_TOSS_FADE1) {
                         outX = item->position.x;
                         outY = (item->position.y - physData->verticalVelocity) + 12.0f;
                         outZ = item->position.z;
                         outDepth = -physData->verticalVelocity + 12.0f;
-                        if (physData->unk_20 == 0) {
+                        if (!physData->unk_20) {
                             hit = npc_raycast_down_sides(COLLISION_CHANNEL_20000, &outX, &outY, &outZ, &outDepth);
                         } else {
                             hit = npc_raycast_down_around(COLLISION_CHANNEL_20000, &outX, &outY, &outZ, &outDepth, 180.0f, 20.0f);
@@ -2462,16 +2461,16 @@ void func_8013559C(ItemEntity* itemEntity) {
 
         if (itemEntity->spawnType != ITEM_SPAWN_MODE_ITEM_BLOCK_SPAWN_ALWAYS) {
             if (itemEntity->spawnType != ITEM_SPAWN_MODE_TOSS_FADE1) {
-                if (physicsData->unk_1C < 60) {
-                    if ((itemEntity->flags & ITEM_ENTITY_FLAG_200000) || ((gGameStatusPtr->frameCounter + flag) & 1)) {
+                if (physicsData->timeLeft < 60) {
+                    if ((itemEntity->flags & ITEM_ENTITY_FLAG_CANT_COLLECT) || ((gGameStatusPtr->frameCounter + flag) & 1)) {
                         itemEntity->flags &= ~ITEM_ENTITY_FLAG_HIDDEN;
                     } else {
                         itemEntity->flags |= ITEM_ENTITY_FLAG_HIDDEN;
                     }
                 }
             } else {
-                if (physicsData->unk_1C < 10) {
-                    itemEntity->alpha = physicsData->unk_1C * 28;
+                if (physicsData->timeLeft < 10) {
+                    itemEntity->alpha = physicsData->timeLeft * 28;
                     itemEntity->flags |= ITEM_ENTITY_FLAG_TRANSPARENT;
                 }
             }
diff --git a/src/a5dd0_len_114e0.c b/src/a5dd0_len_114e0.c
index b5546aced0..1634e5745c 100644
--- a/src/a5dd0_len_114e0.c
+++ b/src/a5dd0_len_114e0.c
@@ -1745,8 +1745,8 @@ s32 entity_get_collision_flags(Entity* entity) {
     return entityFlags;
 }
 
-s32 entity_interacts_with_current_partner(s32 entityIdx) {
-    s32 ret = FALSE;
+s32 entity_try_partner_interaction_trigger(s32 entityIdx) {
+    s32 interacted = FALSE;
     u32 entityType = get_entity_type(entityIdx);
     s32 partnerID = get_current_partner_id();
     Entity* entity;
@@ -1772,7 +1772,7 @@ s32 entity_interacts_with_current_partner(s32 entityIdx) {
                 case ENTITY_TYPE_BOMBABLE_ROCK:
                     entity = get_entity_by_index(entityIdx);
                     entity->flags |= ENTITY_FLAG_PARTNER_COLLISION;
-                    ret = TRUE;
+                    interacted = TRUE;
             }
             break;
         case PARTNER_KOOPER:
@@ -1795,11 +1795,11 @@ s32 entity_interacts_with_current_partner(s32 entityIdx) {
                 case ENTITY_TYPE_SUPER_BLOCK:
                     entity = get_entity_by_index(entityIdx);
                     entity->flags |= ENTITY_FLAG_PARTNER_COLLISION;
-                    ret = TRUE;
+                    interacted = TRUE;
             }
             break;
     }
-    return ret;
+    return interacted;
 }
 
 s32 test_player_entity_aabb(Entity* entity) {
diff --git a/src/entity/jan_iwa/Plants1.c b/src/entity/jan_iwa/Plants1.c
index 926981470a..7bd0c35126 100644
--- a/src/entity/jan_iwa/Plants1.c
+++ b/src/entity/jan_iwa/Plants1.c
@@ -284,7 +284,7 @@ void entity_CymbalPlant_idle(Entity* entity) {
                 data->unk_01++;
                 data->state++;
                 disable_player_input();
-                set_action_state(0);
+                set_action_state(ACTION_STATE_IDLE);
                 play_model_animation(entity->virtualModelIndex, Entity_CymbalPlant_AnimationGrab);
                 sfx_play_sound(SOUND_F2);
                 func_802BB8D4_E2E204(entity);
diff --git a/src/evt/npc_api.c b/src/evt/npc_api.c
index ad9794e9f1..50d88cae10 100644
--- a/src/evt/npc_api.c
+++ b/src/evt/npc_api.c
@@ -269,9 +269,9 @@ ApiStatus NpcMoveTo(Evt* script, s32 isInitialCall) {
     npc_move_heading(npc, npc->moveSpeed, npc->yaw);
 
     if (npc->moveSpeed < 4.0) {
-        func_8003D660(npc, 0);
+        spawn_surface_effects(npc, SURFACE_INTERACT_WALK);
     } else {
-        func_8003D660(npc, 1);
+        spawn_surface_effects(npc, SURFACE_INTERACT_RUN);
     }
 
     dist = dist2D(npc->pos.x, npc->pos.z, npc->moveToPos.x, npc->moveToPos.z);
@@ -351,7 +351,7 @@ ApiStatus _npc_jump_to(Evt* script, s32 isInitialCall, s32 snapYaw) {
         npc->pos.y = npc->moveToPos.y;
         npc->pos.z = npc->moveToPos.z;
         npc->flags &= ~NPC_FLAG_JUMPING;
-        func_8003D660(npc, 2);
+        spawn_surface_effects(npc, SURFACE_INTERACT_LAND);
         return ApiStatus_DONE1;
     }
     return ApiStatus_BLOCK;
diff --git a/src/evt/player_api.c b/src/evt/player_api.c
index 293840b133..a4c2eb1bd9 100644
--- a/src/evt/player_api.c
+++ b/src/evt/player_api.c
@@ -313,7 +313,7 @@ s32 player_jump(Evt* script, s32 isInitialCall, s32 mode) {
                 anim = ANIM_Mario1_TiredIdle;
             }
             suggest_player_anim_allow_backward(anim);
-            func_8003D660(playerNpc, 2);
+            spawn_surface_effects(playerNpc, SURFACE_INTERACT_LAND);
         }
 
         if (mode == 0 || mode == 2) {
diff --git a/src/npc.c b/src/npc.c
index e04d4fd83a..e8d3bfdeae 100644
--- a/src/npc.c
+++ b/src/npc.c
@@ -540,82 +540,81 @@ s32 npc_do_player_collision(Npc* npc) {
 INCLUDE_ASM(s32, "npc", npc_do_player_collision, Npc* npc);
 #endif
 
-void npc_do_gravity(Npc* npc) {
-    if (npc->flags & NPC_FLAG_GRAVITY) {
-        if (npc->flags & NPC_FLAG_JUMPING) {
-            npc->flags &= ~NPC_FLAG_FALLING;
-        } else {
-            f32 xTemp;
-            f32 yTemp;
-            f32 zTemp;
-            f32 length, oldLength;
-            s32 hit;
+// update NPC position using gravitational acceleration = 1.0
+// if the NPC is within 16 units of the floor, they are snapped to it
+void npc_try_apply_gravity(Npc* npc) {
+    f32 x, y, z, testLength;
+    f32 length;
+    s32 hitID;
+    
+    if (!(npc->flags & NPC_FLAG_GRAVITY)) {
+        return;
+    }
 
-            npc->jumpScale = 1.0f;
-            xTemp = npc->pos.x;
-            zTemp = npc->pos.z;
+    if (npc->flags & NPC_FLAG_JUMPING) {
+        npc->flags &= ~NPC_FLAG_GROUNDED;
+        return;
+    }
 
-            npc->jumpVelocity -= npc->jumpScale;
-            npc->pos.y += npc->jumpVelocity;
-            oldLength = length = fabsf(npc->jumpVelocity) + 16.0f;
+    npc->jumpScale = 1.0f;
+    npc->jumpVelocity -= npc->jumpScale;
+    npc->pos.y += npc->jumpVelocity;
 
-            yTemp = npc->pos.y + 13.0f;
+    x = npc->pos.x;
+    y = npc->pos.y + 13;
+    z = npc->pos.z;
+    testLength = length = fabsf(npc->jumpVelocity) + 16;
 
-            if (!(npc->flags & NPC_FLAG_PARTNER)) {
-                hit = npc_raycast_down_sides(npc->collisionChannel, &xTemp, &yTemp, &zTemp, &length);
-            } else {
-                hit = npc_raycast_down_around(npc->collisionChannel, &xTemp, &yTemp, &zTemp, &length, npc->yaw,
-                                             npc->collisionRadius);
-            }
+    if (!(npc->flags & NPC_FLAG_PARTNER)) {
+        hitID = npc_raycast_down_sides(npc->collisionChannel, &x, &y, &z, &length);
+    } else {
+        hitID = npc_raycast_down_around(npc->collisionChannel, &x, &y, &z, &length, npc->yaw, npc->collisionRadius);
+    }
 
-            if (hit && length <= oldLength) {
-                npc->jumpVelocity = 0.0f;
-                npc->flags |= NPC_FLAG_FALLING;
-                npc->pos.y = yTemp;
-                npc->currentFloor = NpcHitQueryColliderID;
-            } else {
-                npc->flags &= ~NPC_FLAG_FALLING;
-            }
-        }
+    if (hitID && length <= testLength) {
+        npc->jumpVelocity = 0.0f;
+        npc->flags |= NPC_FLAG_GROUNDED;
+        npc->pos.y = y;
+        npc->currentFloor = NpcHitQueryColliderID;
+    } else {
+        npc->flags &= ~NPC_FLAG_GROUNDED;
     }
 }
 
-s32 func_800397E8(Npc* npc, f32 velocity) {
-    if (!(npc->flags & (NPC_FLAG_GRAVITY | NPC_FLAG_8))) {
-        f32 x;
-        f32 y;
-        f32 z;
-        f32 length;
-        f32 testLength;
-        s32 phi_v0;
-
-        if (npc->flags & NPC_FLAG_JUMPING) {
-            npc->flags &= ~NPC_FLAG_FALLING;
-            return FALSE;
-        }
-
-        length = testLength = fabsf(velocity) + 16;
-        x = npc->pos.x;
-        y = npc->pos.y + 13;
-        z = npc->pos.z;
-
-        if (!(npc->flags & NPC_FLAG_PARTNER)) {
-            phi_v0 = npc_raycast_down_sides(npc->collisionChannel, &x, &y, &z, &length);
-        } else {
-            phi_v0 = npc_raycast_down_around(npc->collisionChannel, &x, &y, &z, &length, npc->yaw, npc->collisionRadius);
-        }
-
-        if (phi_v0 != 0 && length <= testLength) {
-            npc->pos.y = y;
-            npc->currentFloor = NpcHitQueryColliderID;
-            npc->flags |= NPC_FLAG_FALLING;
-            return TRUE;
-        }
-    } else {
+// perform only collision traces and snapping to ground from gravity code
+s32 npc_try_snap_to_ground(Npc* npc, f32 velocity) {
+    f32 x, y, z, testLength;
+    f32 length;
+    s32 hitID;
+    
+    if (npc->flags & (NPC_FLAG_GRAVITY | NPC_FLAG_8)) {
         return FALSE;
     }
 
-    npc->flags &= ~NPC_FLAG_FALLING;
+    if (npc->flags & NPC_FLAG_JUMPING) {
+        npc->flags &= ~NPC_FLAG_GROUNDED;
+        return FALSE;
+    }
+
+    length = testLength = fabsf(velocity) + 16;
+    x = npc->pos.x;
+    y = npc->pos.y + 13;
+    z = npc->pos.z;
+
+    if (!(npc->flags & NPC_FLAG_PARTNER)) {
+        hitID = npc_raycast_down_sides(npc->collisionChannel, &x, &y, &z, &length);
+    } else {
+        hitID = npc_raycast_down_around(npc->collisionChannel, &x, &y, &z, &length, npc->yaw, npc->collisionRadius);
+    }
+
+    if (hitID != 0 && length <= testLength) {
+        npc->pos.y = y;
+        npc->currentFloor = NpcHitQueryColliderID;
+        npc->flags |= NPC_FLAG_GROUNDED;
+        return TRUE;
+    }
+
+    npc->flags &= ~NPC_FLAG_GROUNDED;
     return FALSE;
 }
 
@@ -650,8 +649,8 @@ void update_npcs(void) {
                     npc->flags &= ~(NPC_FLAG_COLLDING_FORWARD_WITH_WORLD | NPC_FLAG_COLLDING_WITH_WORLD);
 
                     npc_do_world_collision(npc);
-                    npc_do_gravity(npc);
-                    func_800397E8(npc, 0.0f);
+                    npc_try_apply_gravity(npc);
+                    npc_try_snap_to_ground(npc, 0.0f);
                     npc_do_player_collision(npc);
                     npc_do_other_npc_collision(npc);
 
@@ -1705,7 +1704,7 @@ s32 npc_draw_palswap_mode_4(Npc* npc, s32 arg1, Matrix4f mtx) {
 
                 blendAlpha = npc->alpha * npc->alpha2 / 255;
                 temp = blendAlpha < 255;
-                spriteInstanceMask = ((temp) << 31) | 0x20000000;
+                spriteInstanceMask = ((temp) << 31) | DRAW_SPRITE_OVERRIDE_PALETTES;
                 spr_draw_npc_sprite(npc->spriteInstanceID | spriteInstanceMask, arg1, blendAlpha, npc->localPalettes, mtx);
             }
         }
@@ -1713,14 +1712,14 @@ s32 npc_draw_palswap_mode_4(Npc* npc, s32 arg1, Matrix4f mtx) {
 }
 
 void npc_set_decoration(Npc* npc, s32 idx, s32 decorationType) {
-    npc__remove_decoration(npc, idx);
+    npc_remove_decoration_impl(npc, idx);
     npc->decorationType[idx] = decorationType;
     npc->changedDecoration[idx] = 1;
     npc->decorationInitialised[idx] = 0;
 }
 
 void npc_remove_decoration(Npc* npc, s32 idx) {
-    npc__remove_decoration(npc, idx);
+    npc_remove_decoration_impl(npc, idx);
 }
 
 s32 npc_update_decorations(Npc* npc) {
@@ -1753,7 +1752,7 @@ s32 npc_update_decorations(Npc* npc) {
     }
 }
 
-void npc__remove_decoration(Npc* npc, s32 idx) {
+void npc_remove_decoration_impl(Npc* npc, s32 idx) {
     switch (npc->decorationType[idx]) {
         case 0:
             npc_remove_decoration_none(npc, idx);
@@ -2160,7 +2159,9 @@ void func_8003D624(Npc* npc, s32 foldType, s32 arg2, s32 arg3, s32 arg4, s32 arg
     func_8003D3BC(npc);
 }
 
-void func_8003D660(Npc* npc, s32 arg1) {
+//TODO begin split for npc_surfaces
+
+void spawn_surface_effects(Npc* npc, SurfaceInteractMode mode) {
     PartnerActionStatus* temp = &gPartnerActionStatus;
 
     if ((npc->flags & (NPC_FLAG_TOUCHES_GROUND | NPC_FLAG_INVISIBLE)) == NPC_FLAG_TOUCHES_GROUND) {
@@ -2168,61 +2169,58 @@ void func_8003D660(Npc* npc, s32 arg1) {
             s32 surfaceType = get_collider_flags((u16)npc->currentFloor) & COLLIDER_FLAGS_SURFACE_TYPE_MASK;
             switch (surfaceType) {
                 case SURFACE_TYPE_FLOWERS:
-                    func_8003DA38(npc, arg1);
-                    return;
+                    spawn_flower_surface_effects(npc, mode);
+                    break;
                 case SURFACE_TYPE_CLOUD:
-                    func_8003DC38(npc, arg1);
-                    return;
+                    spawn_cloud_surface_effects(npc, mode);
+                    break;
                 case SURFACE_TYPE_SNOW:
                     if ((temp->partnerActionState == PARTNER_ACTION_NONE) || (temp->actingPartner != PARTNER_LAKILESTER)) {
-                        func_8003DFA0(npc, arg1);
-                        return;
+                        spawn_snow_surface_effects(npc, mode);
                     }
                     break;
                 case SURFACE_TYPE_HEDGES:
-                    func_8003E0D4(npc, arg1);
-                    return;
+                    spawn_hedge_surface_effects(npc, mode);
+                    break;
                 case SURFACE_TYPE_WATER:
-                    func_8003E1D0(npc, arg1);
-                    return;
+                    spawn_water_surface_effects(npc, mode);
+                    break;
                 case SURFACE_TYPE_SPIKES:
                 case SURFACE_TYPE_LAVA:
                 case SURFACE_TYPE_DOCK_WALL:
                 case SURFACE_TYPE_SLIDE:
                 default:
-                    func_8003D788(npc, arg1);
-                    return;
+                    spawn_default_surface_effects(npc, mode);
+                    break;
             }
         }
     }
 }
 
-static const f32 padding[2] = { 0.0f, 0.0f }; // todo remove when below funcs are decompiled
-
-void func_8003D788(Npc* npc, s32 arg1) {
-    s32 phi_a2;
+void spawn_default_surface_effects(Npc* npc, SurfaceInteractMode mode) {
+    s32 mapIsStarWay;
     f32 sinTheta;
     f32 cosTheta;
 
-    phi_a2 = 0;
+    mapIsStarWay = FALSE;
     if (gGameStatusPtr->areaID == AREA_HOS) {
-        phi_a2 = gGameStatusPtr->mapID == 2;
+        mapIsStarWay = gGameStatusPtr->mapID == 2; //TODO hard-coded map ID
     }
-    if (arg1 == 2) {
+    if (mode == SURFACE_INTERACT_LAND) {
         f32 x = npc->pos.x;
         f32 y = npc->pos.y + 0.0f;
         f32 z = npc->pos.z;
 
-        if (phi_a2 == 0) {
+        if (!mapIsStarWay) {
             fx_landing_dust(0, x, y, z, D_80077C10);
             D_80077C10 = clamp_angle(D_80077C10 + 35.0f);
         } else {
             fx_misc_particles(3, x, y, z,  13.0f, 10.0f, 1.0f, 5, 30);
         }
-    } else if (arg1 != 0) {
+    } else if (mode != SURFACE_INTERACT_WALK) {
         if (D_80077C14++ >= 4) {
             D_80077C14 = 0;
-            if (phi_a2 == 0) {
+            if (!mapIsStarWay) {
                 sin_cos_rad(DEG_TO_RAD(clamp_angle(-npc->yaw)), &sinTheta, &cosTheta);
                 fx_walking_dust(0, npc->pos.x + (npc->collisionRadius * sinTheta * 0.2f), npc->pos.y + 1.5f,
                                npc->pos.z + (npc->collisionRadius * cosTheta * 0.2f), sinTheta, cosTheta);
@@ -2235,13 +2233,13 @@ void func_8003D788(Npc* npc, s32 arg1) {
     }
 }
 
-void func_8003DA38(Npc* npc, s32 arg1) {
+void spawn_flower_surface_effects(Npc* npc, SurfaceInteractMode mode) {
     f32 theta;
     f32 sinTheta;
     f32 cosTheta;
     f32 x, y, z;
 
-    if (arg1 == 2 && D_80077C1E == 5) {
+    if (mode == SURFACE_INTERACT_LAND && D_80077C1E == 5) {
         x = npc->pos.x;
         y = npc->pos.y + + 14.0f;
         z = npc->pos.z;
@@ -2272,7 +2270,7 @@ void func_8003DA38(Npc* npc, s32 arg1) {
     }
 }
 
-void func_8003DC38(Npc* npc, s32 arg1) {
+void spawn_cloud_surface_effects(Npc* npc, SurfaceInteractMode mode) {
     PlayerStatus* playerStatus = &gPlayerStatus;
     f32 xTemp, yTemp, zTemp;
     f32 xTemp2, yTemp2, zTemp2;
@@ -2283,7 +2281,7 @@ void func_8003DC38(Npc* npc, s32 arg1) {
     s32 i;
 
     D_80077C2C += 0.1f;
-    if (arg1 == 2) {
+    if (mode == SURFACE_INTERACT_LAND) {
         fx_cloud_puff(npc->pos.x, (npc->pos.y + 14.0f) - 5.0f, npc->pos.z, D_80077C24);
 
         D_80077C24 = clamp_angle(D_80077C24 + 35.0f);
@@ -2324,7 +2322,7 @@ void func_8003DC38(Npc* npc, s32 arg1) {
     }
 }
 
-void func_8003DFA0(Npc* npc, s32 arg1) {
+void spawn_snow_surface_effects(Npc* npc, SurfaceInteractMode mode) {
     if (D_80077C30++ >= 4) {
         f32 temp_f20;
         f32 x;
@@ -2340,7 +2338,7 @@ void func_8003DFA0(Npc* npc, s32 arg1) {
     }
 }
 
-void func_8003E0D4(Npc* npc, s32 arg1) {
+void spawn_hedge_surface_effects(Npc* npc, SurfaceInteractMode mode) {
     if (D_80077C38++ >= 4) {
         f32 theta;
         f32 sinTheta;
@@ -2355,7 +2353,7 @@ void func_8003E0D4(Npc* npc, s32 arg1) {
     }
 }
 
-void func_8003E1D0(Npc* npc, s32 arg1) {
+void spawn_water_surface_effects(Npc* npc, SurfaceInteractMode mode) {
     if (D_80077C3A++ >= 4) {
         f32 temp_f20;
         f32 x;
@@ -2370,6 +2368,9 @@ void func_8003E1D0(Npc* npc, s32 arg1) {
     }
 }
 
+//TODO end split for npc_surfaces
+static const f32 padding[2] = { 0.0f, 0.0f }; // remove after splitting
+
 void COPY_set_defeated(s32 mapID, s32 encounterID) {
     EncounterStatus* currentEncounter = &gCurrentEncounter;
     s32 encounterIdx = encounterID / 32;
diff --git a/src/world/area_dgb/dgb_01/dgb_01_5_npc.c b/src/world/area_dgb/dgb_01/dgb_01_5_npc.c
index 9e60ab43e7..cf52ee5dea 100644
--- a/src/world/area_dgb/dgb_01/dgb_01_5_npc.c
+++ b/src/world/area_dgb/dgb_01/dgb_01_5_npc.c
@@ -189,7 +189,7 @@ EvtScript N(EVS_NpcInit_Tubba_Floor1) = {
 
 EvtScript N(EVS_NpcInit_Sentinel_01) = {
     EVT_SET(LVar0, GB_StoryProgress)
-    EVT_IF_GE(LVar0, -29)
+    EVT_IF_GE(LVar0, STORY_CH3_TUBBA_WOKE_UP)
         EVT_CALL(SetNpcFlagBits, NPC_SELF, NPC_FLAG_8 | NPC_FLAG_IGNORE_WORLD_COLLISION, TRUE)
         EVT_CALL(EnableNpcShadow, NPC_SELF, FALSE)
         EVT_CALL(SetNpcAnimation, NPC_SELF, ANIM_Sentinel_Anim01)
@@ -203,7 +203,7 @@ EvtScript N(EVS_NpcInit_Sentinel_01) = {
 
 EvtScript N(EVS_NpcInit_Sentinel_02) = {
     EVT_SET(LVar0, GB_StoryProgress)
-    EVT_IF_GE(LVar0, -29)
+    EVT_IF_GE(LVar0, STORY_CH3_TUBBA_WOKE_UP)
         EVT_CALL(SetNpcFlagBits, NPC_SELF, NPC_FLAG_8 | NPC_FLAG_IGNORE_WORLD_COLLISION, TRUE)
         EVT_CALL(EnableNpcShadow, NPC_SELF, FALSE)
         EVT_CALL(SetNpcAnimation, NPC_SELF, ANIM_Sentinel_Anim01)
@@ -217,7 +217,7 @@ EvtScript N(EVS_NpcInit_Sentinel_02) = {
 
 EvtScript N(EVS_NpcInit_Sentinel_03) = {
     EVT_SET(LVar0, GB_StoryProgress)
-    EVT_IF_GE(LVar0, -29)
+    EVT_IF_GE(LVar0, STORY_CH3_TUBBA_WOKE_UP)
         EVT_CALL(SetNpcFlagBits, NPC_SELF, NPC_FLAG_8 | NPC_FLAG_IGNORE_WORLD_COLLISION, TRUE)
         EVT_CALL(EnableNpcShadow, NPC_SELF, FALSE)
         EVT_CALL(SetNpcAnimation, NPC_SELF, ANIM_Sentinel_Anim01)
@@ -231,7 +231,7 @@ EvtScript N(EVS_NpcInit_Sentinel_03) = {
 
 EvtScript N(EVS_NpcInit_Sentinel_04) = {
     EVT_SET(LVar0, GB_StoryProgress)
-    EVT_IF_GE(LVar0, -29)
+    EVT_IF_GE(LVar0, STORY_CH3_TUBBA_WOKE_UP)
         EVT_CALL(SetNpcFlagBits, NPC_SELF, NPC_FLAG_8 | NPC_FLAG_IGNORE_WORLD_COLLISION, TRUE)
         EVT_CALL(EnableNpcShadow, NPC_SELF, FALSE)
         EVT_CALL(SetNpcAnimation, NPC_SELF, ANIM_Sentinel_Anim01)
diff --git a/src/world/area_kmr/kmr_02/kmr_02_3_npc.c b/src/world/area_kmr/kmr_02/kmr_02_3_npc.c
index 9878fdfdc5..dbc4f657da 100644
--- a/src/world/area_kmr/kmr_02/kmr_02_3_npc.c
+++ b/src/world/area_kmr/kmr_02/kmr_02_3_npc.c
@@ -22,7 +22,7 @@ BSS u8 oldEnvR, oldEnvG, oldEnvB;
 #include "world/common/util/ChangeNpcToPartner.inc.c"
 
 API_CALLABLE(N(func_80242014_8B2084)) {
-    if (get_npc_unsafe(NPC_PARTNER)->flags & NPC_FLAG_FALLING) {
+    if (get_npc_unsafe(NPC_PARTNER)->flags & NPC_FLAG_GROUNDED) {
         return ApiStatus_DONE2;
     } else {
         return ApiStatus_BLOCK;
diff --git a/src/world/common/enemy/ai/AvoidPlayerAI.inc.c b/src/world/common/enemy/ai/AvoidPlayerAI.inc.c
index cae8d4858e..94daed002d 100644
--- a/src/world/common/enemy/ai/AvoidPlayerAI.inc.c
+++ b/src/world/common/enemy/ai/AvoidPlayerAI.inc.c
@@ -132,9 +132,9 @@ void N(AvoidPlayerAI_Chase)(Evt* script, MobileAISettings* npcAISettings, EnemyD
     } else {
         if (npc->currentAnim != enemy->animList[ENEMY_ANIM_INDEX_MELEE_PRE]) {
             if (npc->moveSpeed < 4.0) {
-                func_8003D660(npc, 0);
+                spawn_surface_effects(npc, SURFACE_INTERACT_WALK);
             } else {
-                func_8003D660(npc, 1);
+                spawn_surface_effects(npc, SURFACE_INTERACT_RUN);
             }
             npc_move_heading(npc, npc->moveSpeed, npc->yaw);
         }
diff --git a/src/world/common/enemy/ai/CleftAI.inc.c b/src/world/common/enemy/ai/CleftAI.inc.c
index 143816d300..43bbb236a4 100644
--- a/src/world/common/enemy/ai/CleftAI.inc.c
+++ b/src/world/common/enemy/ai/CleftAI.inc.c
@@ -185,7 +185,7 @@ void N(CleftAI_Tackle)(Evt* script, MobileAISettings* aiSettings, EnemyDetectVol
     f32 posX, posY, posZ;
     s32 phi_s1 = FALSE;
 
-    func_8003D660(npc, 1);
+    spawn_surface_effects(npc, SURFACE_INTERACT_RUN);
     npc_move_heading(npc, npc->moveSpeed, npc->yaw);
 
     if (is_point_within_region(enemy->territory->wander.detectShape,
diff --git a/src/world/common/enemy/ai/GuardAI.inc.c b/src/world/common/enemy/ai/GuardAI.inc.c
index a63daed12a..dfb6809539 100644
--- a/src/world/common/enemy/ai/GuardAI.inc.c
+++ b/src/world/common/enemy/ai/GuardAI.inc.c
@@ -121,7 +121,7 @@ void N(GuardAI_Chase)(Evt* script, GuardAISettings* aiSettings, EnemyDetectVolum
         script->AI_TEMP_STATE = AI_STATE_LOSE_PLAYER;
     } else {
         npc_move_heading(npc, npc->moveSpeed, npc->yaw);
-        func_8003D660(npc, 1);
+        spawn_surface_effects(npc, SURFACE_INTERACT_RUN);
         npc->duration--;
         if (npc->duration == 0) {
             script->AI_TEMP_STATE = AI_STATE_CHASE_INIT;
diff --git a/src/world/common/enemy/ai/MontyMoleAI.inc.c b/src/world/common/enemy/ai/MontyMoleAI.inc.c
index c347b64c42..09b8e03ee4 100644
--- a/src/world/common/enemy/ai/MontyMoleAI.inc.c
+++ b/src/world/common/enemy/ai/MontyMoleAI.inc.c
@@ -114,7 +114,7 @@ static void N(MontyMoleAI_Wander)(Evt* script, MobileAISettings* aiSettings, Ene
         }
         script->functionTemp[1]--;
     }
-    if (!(npc->flags & (NPC_FLAG_8 | NPC_FLAG_FALLING))) {
+    if (!(npc->flags & (NPC_FLAG_8 | NPC_FLAG_GROUNDED))) {
         npc->homePos.x = npc->pos.x;
         npc->homePos.z = npc->pos.z;
     }
diff --git a/src/world/common/enemy/ai/States_PatrolAI.inc.c b/src/world/common/enemy/ai/States_PatrolAI.inc.c
index 86d6708167..49721bb5c9 100644
--- a/src/world/common/enemy/ai/States_PatrolAI.inc.c
+++ b/src/world/common/enemy/ai/States_PatrolAI.inc.c
@@ -69,9 +69,9 @@ void N(PatrolAI_Move)(Evt* script, MobileAISettings* aiSettings, EnemyDetectVolu
 
     if (npc->turnAroundYawAdjustment == 0) {
         if (npc->moveSpeed < 4.0) {
-            func_8003D660(npc, 0);
+            spawn_surface_effects(npc, SURFACE_INTERACT_WALK);
         } else {
-            func_8003D660(npc, 1);
+            spawn_surface_effects(npc, SURFACE_INTERACT_RUN);
         }
         //TODO strange match -- index and array are backwards!
         x = script->AI_PATROL_GOAL_INDEX[enemy->territory->patrol.points].x;
@@ -219,7 +219,7 @@ ApiStatus N(PatrolAI_Chase)(Evt* script, MobileAISettings* aiSettings, EnemyDete
         npc->duration = 25;
         script->AI_TEMP_STATE = AI_STATE_LOSE_PLAYER;
     } else {
-        func_8003D660(npc, 1);
+        spawn_surface_effects(npc, SURFACE_INTERACT_RUN);
         npc_move_heading(npc, npc->moveSpeed, npc->yaw);
         if (npc->duration > 0) {
             npc->duration--;
diff --git a/src/world/common/todo/AwaitPlayerNearNpc.inc.c b/src/world/common/todo/AwaitPlayerNearNpc.inc.c
index c00cbb6150..e4cd78c586 100644
--- a/src/world/common/todo/AwaitPlayerNearNpc.inc.c
+++ b/src/world/common/todo/AwaitPlayerNearNpc.inc.c
@@ -30,7 +30,7 @@ API_CALLABLE(N(func_802408B4_97BEE4)) {
         npc->verticalRenderOffset = 0;
     }
 
-    if (npc->flags & NPC_FLAG_FALLING) {
+    if (npc->flags & NPC_FLAG_GROUNDED) {
         currentEncounter->encounterList[enemy->encounterIndex]->battle = enemy->varTable[0];
         return ApiStatus_DONE2;
     }
diff --git a/src/world/common/todo/CheckPartnerFlags1000.inc.c b/src/world/common/todo/CheckPartnerFlags1000.inc.c
index 952b66d49a..d4ffb398dc 100644
--- a/src/world/common/todo/CheckPartnerFlags1000.inc.c
+++ b/src/world/common/todo/CheckPartnerFlags1000.inc.c
@@ -2,7 +2,7 @@
 #include "npc.h"
 
 API_CALLABLE(N(CheckPartnerFlags1000)) {
-    if (get_npc_unsafe(NPC_PARTNER)->flags & NPC_FLAG_FALLING) {
+    if (get_npc_unsafe(NPC_PARTNER)->flags & NPC_FLAG_GROUNDED) {
         return ApiStatus_DONE2;
     } else {
         return ApiStatus_BLOCK;
diff --git a/src/world/partner/bombette.c b/src/world/partner/bombette.c
index 1a0e352fe1..f5406e60ce 100644
--- a/src/world/partner/bombette.c
+++ b/src/world/partner/bombette.c
@@ -13,7 +13,7 @@ BSS s32 D_802BE938;
 BSS s32 D_802BE93C;
 BSS TweesterPhysics BombetteTweesterPhysics;
 
-void entity_interacts_with_current_partner(s32 arg0);
+void entity_try_partner_interaction_trigger(s32 arg0);
 
 void func_802BD100_317E50(Npc* npc) {
     f32 x, y, z;
@@ -48,12 +48,12 @@ void func_802BD100_317E50(Npc* npc) {
 
         if (!(angle >= 360.0f)) {
             if (NpcHitQueryColliderID >= 0 && (NpcHitQueryColliderID & COLLISION_WITH_ENTITY_BIT) != 0) {
-                entity_interacts_with_current_partner(NpcHitQueryColliderID & ~COLLISION_WITH_ENTITY_BIT);
+                entity_try_partner_interaction_trigger(NpcHitQueryColliderID & ~COLLISION_WITH_ENTITY_BIT);
             }
         }
     } else {
         if (NpcHitQueryColliderID >= 0 && (NpcHitQueryColliderID & COLLISION_WITH_ENTITY_BIT) != 0) {
-            entity_interacts_with_current_partner(NpcHitQueryColliderID & ~COLLISION_WITH_ENTITY_BIT);
+            entity_try_partner_interaction_trigger(NpcHitQueryColliderID & ~COLLISION_WITH_ENTITY_BIT);
         }
     }
 }
@@ -226,7 +226,7 @@ ApiStatus func_802BD758_3184A8(Evt *evt, s32 isInitialCall) {
 
     switch (evt->functionTemp[0]) {
         case 20:
-            if ((playerStatus->inputEnabledCounter != 0) || (playerStatus->flags & PS_FLAG_JUMPING) || !(npc->flags & NPC_FLAG_FALLING)) {
+            if ((playerStatus->inputEnabledCounter != 0) || (playerStatus->flags & PS_FLAG_JUMPING) || !(npc->flags & NPC_FLAG_GROUNDED)) {
                 return ApiStatus_DONE2;
             }
             disable_player_input();
@@ -238,7 +238,7 @@ ApiStatus func_802BD758_3184A8(Evt *evt, s32 isInitialCall) {
             npc->flags &= ~(NPC_FLAG_JUMPING | NPC_FLAG_GRAVITY | NPC_FLAG_IGNORE_WORLD_COLLISION | NPC_FLAG_8);
             partnerActionStatus->partnerActionState = PARTNER_ACTION_USE;
             partnerActionStatus->actingPartner = PARTNER_BOMBETTE;
-            D_802BE920 = func_800EF4E0();
+            D_802BE920 = partner_force_player_flip_done();
             enable_npc_blur(npc);
             npc->duration = 4;
             npc->yaw = atan2(npc->pos.x, npc->pos.z, playerStatus->position.x, playerStatus->position.z);
@@ -316,7 +316,7 @@ ApiStatus func_802BD758_3184A8(Evt *evt, s32 isInitialCall) {
             if (evt->functionTemp[1] < 45) {
                 if (!(npc->flags & NPC_FLAG_COLLDING_WITH_WORLD) && (D_802BE938 == 0)) {
                     npc_move_heading(npc, npc->moveSpeed, npc->yaw);
-                    func_8003D660(npc, 0);
+                    spawn_surface_effects(npc, SURFACE_INTERACT_WALK);
                 } else {
                     D_802BE938 = 1;
                 }
@@ -396,7 +396,7 @@ ApiStatus func_802BD758_3184A8(Evt *evt, s32 isInitialCall) {
                     break;
             }
             exec_ShakeCam1(0, 0, 20);
-            func_8003D660(npc, 2);
+            spawn_surface_effects(npc, SURFACE_INTERACT_LAND);
             collisionStatus->bombetteExploded = 0;
             collisionStatus->bombetteExplosionPos.x = npc->pos.x;
             collisionStatus->bombetteExplosionPos.y = npc->pos.y;
@@ -460,7 +460,7 @@ ApiStatus func_802BD758_3184A8(Evt *evt, s32 isInitialCall) {
                 if (fabsf(playerStatus->position.y - npc->pos.y) < 500.0) {
                     evt->functionTemp[0] = 8;
                     break;
-                } else if (func_800397E8(npc, npc->jumpVelocity)) {
+                } else if (npc_try_snap_to_ground(npc, npc->jumpVelocity)) {
                     evt->functionTemp[0] = 7;
                     break;
                 }
diff --git a/src/world/partner/bow.c b/src/world/partner/bow.c
index 9e0a3a5f4c..b054db338b 100644
--- a/src/world/partner/bow.c
+++ b/src/world/partner/bow.c
@@ -238,7 +238,7 @@ ApiStatus BowUseAbility(Evt* script, s32 isInitialCall) {
             partnerActionStatus->partnerActionState = 1;
             partnerActionStatus->actingPartner = 9;
             playerStatus->flags |= PS_FLAG_HAZARD_INVINCIBILITY;
-            func_800EF4E0();
+            partner_force_player_flip_done();
             bow->moveToPos.x = playerStatus->position.x;
             bow->moveToPos.y = playerStatus->position.y + (playerStatus->colliderHeight * 0.5f);
             bow->moveToPos.z = playerStatus->position.z;
diff --git a/src/world/partner/goombario.c b/src/world/partner/goombario.c
index c04004b13f..fc20e96f57 100644
--- a/src/world/partner/goombario.c
+++ b/src/world/partner/goombario.c
@@ -213,7 +213,7 @@ s32 world_goombario_can_pause(Npc* goombario) {
         return FALSE;
     }
 
-    if ((goombario->flags & (NPC_FLAG_FALLING | NPC_FLAG_JUMPING)) != NPC_FLAG_FALLING) {
+    if ((goombario->flags & (NPC_FLAG_GROUNDED | NPC_FLAG_JUMPING)) != NPC_FLAG_GROUNDED) {
         return new_var = 0;
         do { } while (new_var); // why though
     }
@@ -247,7 +247,7 @@ ApiStatus func_802BD5D8_3174F8(Evt* script, s32 isInitialCall) {
 
     switch (script->functionTemp[0]) {
         case 40:
-            if (!(goombario->flags & NPC_FLAG_FALLING) || playerStatus->inputEnabledCounter != 0) {
+            if (!(goombario->flags & NPC_FLAG_GROUNDED) || playerStatus->inputEnabledCounter != 0) {
                 script->varTable[0] = -1;
                 return ApiStatus_DONE2;
             }
diff --git a/src/world/partner/kooper.c b/src/world/partner/kooper.c
index be04744912..e037dc07ec 100644
--- a/src/world/partner/kooper.c
+++ b/src/world/partner/kooper.c
@@ -2,86 +2,101 @@
 #include "../src/world/partners.h"
 #include "sprite/npc/WorldKooper.h"
 
-s32 entity_interacts_with_current_partner(s32);
+s32 entity_try_partner_interaction_trigger(s32);
 s32 test_item_entity_position(f32, f32, f32, f32);
 s32 npc_raycast_up_corner(s32 ignoreFlags, f32* x, f32* y, f32* z, f32* length);
 void fx_damage_stars(s32, f32, f32, f32, f32, f32, f32, s32);
-void func_801341B0(s32);
+void auto_collect_item_entity(s32);
 
-BSS s32 D_802BEC50;
-BSS s32 D_802BEC54;
-BSS s32 D_802BEC58;
+BSS s32 KooperShellTossHoldTime;
+BSS s32 KooperTriggeredBattle;
+BSS s32 ShellTossPlayerFacingLeft;
 BSS s32 D_802BEC5C;
-BSS s32 D_802BEC60;
-BSS s32 D_802BEC64;
-BSS s32 D_802BEC68;
-BSS s32 D_802BEC6C;
-BSS f32 D_802BEC70;
-BSS f32 D_802BEC74;
-BSS f32 D_802BEC78;
+BSS s32 ShellTossKickFalling;
+BSS s32 ShellTossControlsPlayer;
+BSS s32 KooperHeldItemIdx;
+BSS s32 KooperHasItem;
+BSS f32 ShellTossPosX;
+BSS f32 ShellTossPosY;
+BSS f32 ShellTossPosZ;
 BSS s32 D_802BEC7C;
 
-s32 D_802BEB40_31CB60 = 0;
+enum {
+    SHELL_TOSS_HITBOX_DISABLED      = 0,
+    SHELL_TOSS_HITBOX_ENABLED       = 1,
+    SHELL_TOSS_HITBOX_HIT_ENEMY     = 2,
+};
 
-s32 func_802BD100_31B120(Npc* npc) {
+s32 ShellTossHitboxState = SHELL_TOSS_HITBOX_DISABLED;
+
+s32 kooper_lateral_hit_interactable_entity(Npc* npc) {
     if (NpcHitQueryColliderID < 0) {
-        return 0;
+        return FALSE;
     }
 
     if (!(NpcHitQueryColliderID & COLLISION_WITH_ENTITY_BIT)) {
-        return 0;
+        return FALSE;
     }
 
-    return entity_interacts_with_current_partner(NpcHitQueryColliderID & ~COLLISION_WITH_ENTITY_BIT);
+    return entity_try_partner_interaction_trigger(NpcHitQueryColliderID & ~COLLISION_WITH_ENTITY_BIT);
 }
 
-void func_802BD144_31B164(Npc* kooper) {
-    if (NpcHitQueryColliderID >= 0 && NpcHitQueryColliderID & COLLISION_WITH_ENTITY_BIT) {
-        entity_interacts_with_current_partner(NpcHitQueryColliderID & ~COLLISION_WITH_ENTITY_BIT);
+void kooper_vertical_hit_interactable_entity(Npc* kooper) {
+    if (NpcHitQueryColliderID < 0) {
+        return;
     }
+
+    if (!(NpcHitQueryColliderID & COLLISION_WITH_ENTITY_BIT)) {
+        return;
+    }
+
+    entity_try_partner_interaction_trigger(NpcHitQueryColliderID & ~COLLISION_WITH_ENTITY_BIT);
 }
 
-s32 func_802BD17C_31B19C(Npc* kooper) {
-    D_802BEC68 = test_item_entity_position(kooper->pos.x, kooper->pos.y, kooper->pos.z, kooper->collisionRadius);
+s32 kooper_check_for_item_collision(Npc* kooper) {
+    KooperHeldItemIdx = test_item_entity_position(kooper->pos.x, kooper->pos.y, kooper->pos.z, kooper->collisionRadius);
 
-    if (D_802BEC68 < 0) {
-        return 0;
-    } else {
-        D_802BEC6C = 1;
-        gOverrideFlags |= GLOBAL_OVERRIDES_40;
-        set_item_entity_flags(D_802BEC68, ITEM_ENTITY_FLAG_200000);
-        return 1;
+    if (KooperHeldItemIdx < 0) {
+        return FALSE;
     }
+
+    KooperHasItem = TRUE;
+    gOverrideFlags |= GLOBAL_OVERRIDES_40;
+    set_item_entity_flags(KooperHeldItemIdx, ITEM_ENTITY_FLAG_CANT_COLLECT);
+    return TRUE;
 }
 
 void world_kooper_init(Npc* kooper) {
     kooper->collisionHeight = 37;
     kooper->collisionRadius = 24;
     kooper->collisionChannel = COLLISION_CHANNEL_10000;
-    D_802BEC54 = 0;
+    KooperTriggeredBattle = FALSE;
 }
 
-ApiStatus KooperTakeOut(Evt* script, s32 isInitialCall) {
+API_CALLABLE(KooperTakeOut) {
     Npc* kooper = script->owner2.npc;
 
     if (isInitialCall) {
         partner_init_get_out(kooper);
     }
 
-    return partner_get_out(kooper) ? ApiStatus_DONE1 : ApiStatus_BLOCK;
+    if (partner_get_out(kooper)) {
+        return ApiStatus_DONE1;
+    } else {
+        return ApiStatus_BLOCK;
+    }
 }
 
-EvtScript world_kooper_take_out = {
+EvtScript EVS_WorldKooperTakeOut = {
     EVT_CALL(KooperTakeOut)
     EVT_RETURN
     EVT_END
 };
 
 BSS TweesterPhysics KooperTweesterPhysics;
-
 TweesterPhysics* KooperTweesterPhysicsPtr = &KooperTweesterPhysics;
 
-ApiStatus KooperUpdate(Evt* script, s32 isInitialCall) {
+API_CALLABLE(KooperUpdate) {
     PlayerData* playerData = &gPlayerData;
     Npc* kooper = script->owner2.npc;
     f32 sinAngle, cosAngle, liftoffVelocity;
@@ -164,13 +179,13 @@ ApiStatus KooperUpdate(Evt* script, s32 isInitialCall) {
     return ApiStatus_BLOCK;
 }
 
-EvtScript world_kooper_update = {
+EvtScript EVS_WorldKooperUpdate = {
     EVT_CALL(KooperUpdate)
     EVT_RETURN
     EVT_END
 };
 
-void func_802BD5F4_31B614(Npc* kooper) {
+void kooper_try_cancel_tweester(Npc* kooper) {
     if (TweesterTouchingPartner != NULL) {
         TweesterTouchingPartner = NULL;
         kooper->flags = KooperTweesterPhysicsPtr->prevFlags;
@@ -179,427 +194,453 @@ void func_802BD5F4_31B614(Npc* kooper) {
     }
 }
 
-ApiStatus func_802BD638_31B658(Evt* script, s32 isInitialCall) {
+API_CALLABLE(KooperUseAbility) {
     Camera* cam;
-    ItemEntity* itemGrabbed;
+    ItemEntity* heldItem;
     EncounterStatus* currentEncounter = &gCurrentEncounter;
     PlayerStatus* playerStatus = &gPlayerStatus;
     Npc* kooper = script->owner2.npc;
     PartnerActionStatus* partnerActionStatus = &gPartnerActionStatus;
     CollisionStatus* collisionStatus = &gCollisionStatus;
-    f32 sp20, sp24, sp28, sp2C;
-    s32 phi_v0_4 = 0;
-    f32 temp_f20_3;
-    s32 tempVar;
-    f32 clamp;
+    f32 posX, posY, posZ, hitLength;
+    f32 testLength;
+    s32 actionState;
+    f32 moveAngle;
     f32 colheight;
-    f32 temp2;
+    f32 angleToStartPos;
 
-    if (currentEncounter->unk_08 == 0) {
-        if (isInitialCall) {
-            func_802BD5F4_31B614(kooper);
-            if (playerStatus->animFlags & PA_FLAG_CHANGING_MAP) {
+    #define USE_STATE functionTemp[0]
+    enum {
+        SHELL_TOSS_STATE_BEGIN      = 20,
+        SHELL_TOSS_STATE_GATHER     = 21,
+        SHELL_TOSS_STATE_JUMP       = 2,
+        SHELL_TOSS_STATE_KICK       = 3,
+        SHELL_TOSS_STATE_PICKUP     = 4,
+        SHELL_TOSS_STATE_HOLD       = 5,
+        SHELL_TOSS_STATE_RETURN     = 7,
+        SHELL_TOSS_STATE_FINISH     = 0,
+    };
+
+    if (currentEncounter->unk_08 != 0) {
+        return ApiStatus_BLOCK;
+    }
+
+    if (isInitialCall) {
+        kooper_try_cancel_tweester(kooper);
+        if (playerStatus->animFlags & PA_FLAG_CHANGING_MAP) {
+            return ApiStatus_DONE2;
+        }
+
+        if (!KooperTriggeredBattle) {
+            actionState = playerStatus->actionState;
+            if (actionState == ACTION_STATE_IDLE
+             || actionState == ACTION_STATE_WALK
+             || actionState == ACTION_STATE_RUN
+            ) {
+                script->USE_STATE = SHELL_TOSS_STATE_BEGIN;
+            } else {
+                return ApiStatus_DONE2;
+            }
+        } else if (partnerActionStatus->partnerActionState == PARTNER_ACTION_NONE) {
+            partnerActionStatus->partnerActionState = PARTNER_ACTION_KOOPER_GATHER;
+            partnerActionStatus->actingPartner = PARTNER_KOOPER;
+            script->USE_STATE = SHELL_TOSS_STATE_HOLD;
+            kooper->currentAnim = ANIM_WorldKooper_SpinShell;
+            KooperShellTossHoldTime = 30;
+        }
+    }
+
+    switch (script->USE_STATE) {
+        case SHELL_TOSS_STATE_BEGIN:
+            if (playerStatus->inputEnabledCounter != 0
+             || playerStatus->timeInAir != 0
+             || !(kooper->flags & NPC_FLAG_GROUNDED)
+            ) {
                 return ApiStatus_DONE2;
             }
 
-            if (D_802BEC54 == 0) {
-                tempVar = playerStatus->actionState;
-                if (tempVar == ACTION_STATE_IDLE || tempVar == ACTION_STATE_WALK || tempVar == ACTION_STATE_RUN) {
-                    script->functionTemp[0] = 20;
-                } else {
-                    return ApiStatus_DONE2;
-                }
-            } else if (partnerActionStatus->partnerActionState == PARTNER_ACTION_NONE) {
-                partnerActionStatus->partnerActionState = PARTNER_ACTION_KOOPER_1;
-                partnerActionStatus->actingPartner = PARTNER_KOOPER;
-                script->functionTemp[0] = 5;
-                kooper->currentAnim = ANIM_WorldKooper_SpinShell;
-                D_802BEC50 = 30;
+            disable_player_input();
+            script->functionTemp[2] = playerStatus->inputEnabledCounter;
+            ShellTossControlsPlayer = TRUE;
+            ShellTossHitboxState = SHELL_TOSS_HITBOX_DISABLED;
+            KooperHasItem = FALSE;
+            kooper->flags &= ~(NPC_FLAG_GRAVITY | NPC_FLAG_JUMPING | NPC_FLAG_8);
+            kooper->flags |= (NPC_FLAG_IGNORE_PLAYER_COLLISION | NPC_FLAG_IGNORE_WORLD_COLLISION);
+            partnerActionStatus->actingPartner = PARTNER_KOOPER;
+            partnerActionStatus->partnerActionState = PARTNER_ACTION_KOOPER_GATHER;
+            ShellTossPlayerFacingLeft = partner_force_player_flip_done();
+            enable_npc_blur(kooper);
+            kooper->duration = 4;
+            kooper->yaw = atan2(kooper->pos.x, kooper->pos.z,
+                                playerStatus->position.x, playerStatus->position.z);
+            script->USE_STATE++;
+            break;
+
+        case SHELL_TOSS_STATE_GATHER:
+            if (playerStatus->actionState == ACTION_STATE_HIT_FIRE
+             || playerStatus->actionState == ACTION_STATE_KNOCKBACK
+             || playerStatus->actionState == ACTION_STATE_HIT_LAVA
+             || playerStatus->timeInAir != 0
+            ) {
+                suggest_player_anim_allow_backward(ANIM_Mario1_Idle);
+                script->USE_STATE = SHELL_TOSS_STATE_FINISH;
+                break;
             }
-        }
 
-        switch (script->functionTemp[0]) {
-            case 20:
-                if (playerStatus->inputEnabledCounter == 0) {
-                    if (playerStatus->timeInAir == 0) {
-                        if (kooper->flags & NPC_FLAG_FALLING) {
-                            disable_player_input();
-                            script->functionTemp[2] = playerStatus->inputEnabledCounter;
-                            D_802BEC64 = 1;
-                            D_802BEB40_31CB60 = 0;
-                            D_802BEC6C = 0;
-                            kooper->flags &= ~(NPC_FLAG_GRAVITY | NPC_FLAG_JUMPING | NPC_FLAG_8);
-                            kooper->flags |= (NPC_FLAG_IGNORE_PLAYER_COLLISION | NPC_FLAG_IGNORE_WORLD_COLLISION);
-                            partnerActionStatus->actingPartner = PARTNER_KOOPER;
-                            partnerActionStatus->partnerActionState = PARTNER_ACTION_KOOPER_1;
-                            D_802BEC58 = func_800EF4E0();
-                            enable_npc_blur(kooper);
-                            kooper->duration = 4;
-                            kooper->yaw = atan2(kooper->pos.x, kooper->pos.z,
-                                                playerStatus->position.x, playerStatus->position.z);
-                            script->functionTemp[0]++;
-                        } else {
-                            return ApiStatus_DONE2;
-                        }
-                    } else {
-                        return ApiStatus_DONE2;
-                    }
-                } else {
-                    return ApiStatus_DONE2;
-                }
+            suggest_player_anim_allow_backward(ANIM_Mario1_BeforeJump);
+            kooper->moveToPos.x = ShellTossPosX = playerStatus->position.x;
+            kooper->moveToPos.y = ShellTossPosY = playerStatus->position.y;
+            kooper->moveToPos.z = ShellTossPosZ = playerStatus->position.z;
+            kooper->currentAnim = ANIM_WorldKooper_Run;
+            add_vec2D_polar(&kooper->moveToPos.x, &kooper->moveToPos.z,
+                            playerStatus->colliderDiameter / 3, playerStatus->targetYaw);
+            moveAngle = clamp_angle(playerStatus->targetYaw + (ShellTossPlayerFacingLeft ? 90.0f : -90.0f));
+            add_vec2D_polar(&kooper->moveToPos.x, &kooper->moveToPos.z,
+                            playerStatus->colliderDiameter / 4, moveAngle);
+            kooper->pos.x += (kooper->moveToPos.x - kooper->pos.x) / kooper->duration;
+            kooper->pos.y += (kooper->moveToPos.y - kooper->pos.y) / kooper->duration;
+            kooper->pos.z += (kooper->moveToPos.z - kooper->pos.z) / kooper->duration;
+
+            kooper->duration--;
+            if (kooper->duration != 0) {
                 break;
+            }
 
-            case 21:
-                //TODO: make if statement less bad
-                if ((((u8)playerStatus->actionState - 0x15) < 3U) || (playerStatus->timeInAir != 0)) {
+            disable_npc_blur(kooper);
+            if (script->functionTemp[2] < playerStatus->inputEnabledCounter) {
+                if (!(playerStatus->animFlags & PA_FLAG_CHANGING_MAP)) {
                     suggest_player_anim_allow_backward(ANIM_Mario1_Idle);
-                    script->functionTemp[0] = 0;
-                    break;
                 } else {
-                    suggest_player_anim_allow_backward(ANIM_Mario1_BeforeJump);
-                    kooper->moveToPos.x = D_802BEC70 = playerStatus->position.x;
-                    kooper->moveToPos.y = D_802BEC74 = playerStatus->position.y;
-                    kooper->moveToPos.z = D_802BEC78 = playerStatus->position.z;
-                    kooper->currentAnim = ANIM_WorldKooper_Run;
-                    add_vec2D_polar(&kooper->moveToPos.x, &kooper->moveToPos.z,
-                                    playerStatus->colliderDiameter / 3, playerStatus->targetYaw);
-                    clamp = clamp_angle(playerStatus->targetYaw + ((D_802BEC58 != 0) ? 90.0f : -90.0f));
-                    add_vec2D_polar(&kooper->moveToPos.x, &kooper->moveToPos.z,
-                                    playerStatus->colliderDiameter / 4, clamp);
-                    kooper->pos.x = (kooper->pos.x + ((kooper->moveToPos.x - kooper->pos.x) / kooper->duration));
-                    kooper->pos.y = (kooper->pos.y + ((kooper->moveToPos.y - kooper->pos.y) / kooper->duration));
-                    kooper->pos.z = (kooper->pos.z + ((kooper->moveToPos.z - kooper->pos.z) / kooper->duration));
-                    kooper->duration -= 1;
-
-                    if (kooper->duration << 0x10) {
-                        break;
-                    }
-                    disable_npc_blur(kooper);
-                    if (script->functionTemp[2] < playerStatus->inputEnabledCounter) {
-                        if (!(playerStatus->animFlags & PA_FLAG_CHANGING_MAP)) {
-                            suggest_player_anim_allow_backward(ANIM_Mario1_Idle);
-                        } else {
-                            suggest_player_anim_allow_backward(ANIM_Mario1_Run);
-                        }
-                        script->functionTemp[0] = 0;
-                        break;
-                    } else {
-                        kooper->yaw = playerStatus->targetYaw;
-                        kooper->jumpVelocity = 18.0f;
-                        kooper->jumpScale = 3.0f;
-                        kooper->currentAnim = ANIM_WorldKooper_EnterShell;
-                        kooper->collisionHeight = 12;
-
-                        kooper->moveToPos.y = playerStatus->position.y;
-                        kooper->moveToPos.z = playerStatus->position.y + playerStatus->colliderHeight / 3;
-                        playerStatus->flags |= PS_FLAG_JUMPING;
-                        gCameras[CAM_DEFAULT].moveFlags |= CAMERA_MOVE_IGNORE_PLAYER_Y;
-
-                        suggest_player_anim_allow_backward(ANIM_Mario1_Jump);
-                        D_802BEC60 = 0;
-                        sfx_play_sound_at_npc(SOUND_JUMP_2081, SOUND_SPACE_MODE_0, NPC_PARTNER);
-                        script->functionTemp[0] = 2;
-                    }
-                }
-
-            case 2:
-                if ((u8)playerStatus->actionState == ACTION_STATE_HIT_FIRE ||
-                    (u8)playerStatus->actionState == ACTION_STATE_KNOCKBACK ||
-                    (u8)playerStatus->actionState == ACTION_STATE_HIT_LAVA) {
-                    script->functionTemp[0] = 0;
-                } else {
-                    kooper->jumpVelocity -= kooper->jumpScale;
-                    playerStatus->position.y += kooper->jumpVelocity;
-                    if (kooper->jumpVelocity < 0.0f) {
-                        if (D_802BEC60 == 0) {
-                            D_802BEC60 = 1;
-                            suggest_player_anim_allow_backward(ANIM_Mario1_Fall);
-                        }
-                    }
-
-                    sp20 = playerStatus->position.x;
-                    sp24 = (playerStatus->position.y + playerStatus->colliderHeight / 2) - kooper->jumpVelocity;
-                    sp28 = playerStatus->position.z;
-                    sp2C = playerStatus->colliderHeight / 2;
-                    temp_f20_3 = sp2C;
-
-                    if ((npc_raycast_up(0x10000, &sp20, &sp24, &sp28, &sp2C) != 0) && (sp2C < temp_f20_3)) {
-                        collisionStatus->currentCeiling = NpcHitQueryColliderID;
-                        playerStatus->position.y = sp24 - playerStatus->colliderHeight;
-                        func_802BD144_31B164(kooper);
-                    }
-
-                    if (!(kooper->jumpVelocity > 0.0f) && (playerStatus->position.y < kooper->moveToPos.z)) {
-                        D_802BEC5C = 0;
-                        kooper->flags &= ~NPC_FLAG_IGNORE_PLAYER_COLLISION;
-                        partnerActionStatus->actingPartner = PARTNER_KOOPER;
-                        partnerActionStatus->partnerActionState = PARTNER_ACTION_KOOPER_2;
-                        kooper->rotation.z = 0.0f;
-                        kooper->planarFlyDist = 0.0f;
-                        kooper->moveSpeed = 8.0f;
-                        kooper->currentAnim = ANIM_WorldKooper_SpinShell;
-                        D_802BEB40_31CB60 = 1;
-                        fx_damage_stars(3, kooper->pos.x, kooper->pos.y + kooper->collisionHeight, kooper->pos.z,
-                                sin_deg(playerStatus->targetYaw), -1.0f, -cos_deg(playerStatus->targetYaw), 3);
-                        start_bounce_b();
-
-                        if (D_802BEC64 != 0) {
-                            enable_player_input();
-                            D_802BEC64 = 0;
-                        }
-
-                        script->functionTemp[0] = 3;
-                        D_802BEC60 = 0;
-                        gCameras[CAM_DEFAULT].moveFlags |= CAMERA_MOVE_IGNORE_PLAYER_Y;
-                        sfx_play_sound_at_npc(SOUND_283, SOUND_SPACE_MODE_0, NPC_PARTNER);
-                        sfx_play_sound_at_npc(SOUND_284, SOUND_SPACE_MODE_0, NPC_PARTNER);
-                    }
+                    suggest_player_anim_allow_backward(ANIM_Mario1_Run);
                 }
+                script->USE_STATE = SHELL_TOSS_STATE_FINISH;
                 break;
+            }
 
-            case 3:
-                //TODO: make if statement less bad
-                if (((u8)playerStatus->actionState - 0x15) > 1U) {
-                    sp20 = kooper->pos.x;
-                    sp24 = kooper->pos.y;
-                    sp28 = kooper->pos.z;
+            kooper->yaw = playerStatus->targetYaw;
+            kooper->jumpVelocity = 18.0f;
+            kooper->jumpScale = 3.0f;
+            kooper->currentAnim = ANIM_WorldKooper_EnterShell;
+            kooper->collisionHeight = 12;
 
-                    if (npc_test_move_taller_with_slipping(0x8000, &sp20, &sp24, &sp28, kooper->moveSpeed,
-                                                           kooper->yaw - 20.0f, kooper->collisionHeight,
-                                                           (kooper->collisionRadius / 2)) != 0) {
-                        if (func_802BD100_31B120(kooper) == 0) {
-                            sfx_play_sound_at_npc(SOUND_IMMUNE, SOUND_SPACE_MODE_0, NPC_PARTNER);
-                        }
+            kooper->moveToPos.y = playerStatus->position.y;
+            kooper->moveToPos.z = playerStatus->position.y + playerStatus->colliderHeight / 3;
+            playerStatus->flags |= PS_FLAG_JUMPING;
+            gCameras[CAM_DEFAULT].moveFlags |= CAMERA_MOVE_IGNORE_PLAYER_Y;
 
-                        temp_f20_3 = sin_deg(kooper->yaw);
-                        fx_damage_stars(3, kooper->pos.x, kooper->pos.y + kooper->collisionHeight, kooper->pos.z,
-                                temp_f20_3, -1.0f, -cos_deg(kooper->yaw), 1);
-                        sfx_play_sound_at_npc(SOUND_0, SOUND_SPACE_MODE_0, NPC_PARTNER);
-                        script->functionTemp[0] = 7;
-                        break;
-                    }
+            suggest_player_anim_allow_backward(ANIM_Mario1_Jump);
+            ShellTossKickFalling = FALSE;
+            sfx_play_sound_at_npc(SOUND_JUMP_2081, SOUND_SPACE_MODE_0, NPC_PARTNER);
+            script->USE_STATE = SHELL_TOSS_STATE_JUMP;
+            // fallthrough
 
-                    sp20 = kooper->pos.x;
-                    sp24 = kooper->pos.y;
-                    sp28 = kooper->pos.z;
-
-                    if ((npc_test_move_taller_with_slipping(0x8000, &sp20, &sp24, &sp28, kooper->moveSpeed,
-                                                            kooper->yaw + 20.0f, kooper->collisionHeight,
-                                                            kooper->collisionRadius / 2) == 0) &&
-                                                            (sp20 = kooper->pos.x, sp24 = kooper->pos.y,
-                                                            sp28 = kooper->pos.z,
-                                                            (npc_test_move_taller_with_slipping(0x8000, &sp20, &sp24,
-                                                            &sp28, kooper->moveSpeed, kooper->yaw,
-                                                            kooper->collisionHeight,
-                                                            kooper->collisionRadius / 2)== 0))) {
-                        kooper->pos.x = sp20;
-                        kooper->pos.y = sp24;
-                        kooper->pos.z = sp28;
-                        kooper->planarFlyDist += kooper->moveSpeed;
-                        func_8003D660(kooper, 1);
-                        kooper->moveSpeed += 2.0;
-
-                        if (kooper->moveSpeed > 14.0) {
-                            kooper->moveSpeed = 14.0f;
-                        }
-
-                        if (!(func_800397E8(kooper, 6.0f) || playerStatus->flags & (PS_FLAG_JUMPING | PS_FLAG_FALLING))) {
-                            kooper->pos.y = (kooper->pos.y + ((playerStatus->position.y - kooper->pos.y) / 10.0f));
-                        }
-
-                        npc_do_other_npc_collision(kooper);
-
-                        if (!(kooper->flags & NPC_FLAG_COLLIDING_WITH_NPC)) {
-                            if (func_802BD17C_31B19C(kooper) != 0) {
-                                sfx_play_sound_at_npc(SOUND_286, SOUND_SPACE_MODE_0, NPC_PARTNER);
-                                temp_f20_3 = sin_deg(kooper->yaw);
-                                fx_damage_stars(3, kooper->pos.x, kooper->pos.y + kooper->collisionHeight, kooper->pos.z,
-                                          temp_f20_3, -1.0f, -cos_deg(kooper->yaw), 1);
-                                sfx_play_sound_at_npc(SOUND_0, SOUND_SPACE_MODE_0, NPC_PARTNER);
-                                script->functionTemp[0] = 4;
-                                D_802BEC50 = 8;
-                                kooper->moveSpeed -= 4.0;
-                                if (kooper->moveSpeed < 0.01) {
-                                    kooper->moveSpeed = 0.01f;
-                                    kooper->planarFlyDist += 1.0;
-                                }
-                            }
-                            else if (D_802BEB40_31CB60 == 2) {
-                                sfx_play_sound_at_npc(SOUND_0, SOUND_SPACE_MODE_0, NPC_PARTNER);
-                                script->functionTemp[0] = 5;
-                                D_802BEC50 = 30;
-                                kooper->moveSpeed = 0.0f;
-                            } else {
-                                if (kooper->planarFlyDist > 140.0f) {
-                                    label2:
-                                    script->functionTemp[0] = 7;
-                                    kooper->moveSpeed = 0.0f;
-                                    sfx_play_sound_at_npc(SOUND_0, SOUND_SPACE_MODE_0, NPC_PARTNER);
-                                }
-
-                                else if (kooper->planarFlyDist > 105.0f) {
-                                    kooper->moveSpeed -= 4.0;
-                                    if (kooper->moveSpeed < 0.01) {
-                                        kooper->moveSpeed = 0.01f;
-                                        kooper->planarFlyDist += 1.0;
-                                    }
-                                }
-                                break;
-                            }
-                        } else {
-                            //TODO get rid of label
-                            goto label2;
-                        }
-                    } else {
-                        if (func_802BD100_31B120(kooper) == 0) {
-                            sfx_play_sound_at_npc(SOUND_IMMUNE, SOUND_SPACE_MODE_0, NPC_PARTNER);
-                        }
-
-                        temp_f20_3 = sin_deg(kooper->yaw);
-                        fx_damage_stars(3, kooper->pos.x, kooper->pos.y + kooper->collisionHeight, kooper->pos.z,
-                                temp_f20_3, -1.0f, -cos_deg(kooper->yaw), 1);
-                        sfx_play_sound_at_npc(SOUND_0, SOUND_SPACE_MODE_0, NPC_PARTNER);
-                        script->functionTemp[0] = 7;
-                    }
-                } else {
-                    script->functionTemp[0] = 0;
-                }
+        case SHELL_TOSS_STATE_JUMP:
+            if (playerStatus->actionState == ACTION_STATE_HIT_FIRE
+             || playerStatus->actionState == ACTION_STATE_KNOCKBACK
+             || playerStatus->actionState == ACTION_STATE_HIT_LAVA
+            ) {
+                script->USE_STATE = SHELL_TOSS_STATE_FINISH;
                 break;
-            case 4:
-                sp20 = kooper->pos.x;
-                sp24 = kooper->pos.y;
-                sp28 = kooper->pos.z;
+            }
 
-                npc_test_move_taller_with_slipping(0x8000, &sp20, &sp24, &sp28, kooper->moveSpeed, kooper->yaw,
-                                                   kooper->collisionHeight, ( kooper->collisionRadius / 2));
-                kooper->pos.x = sp20;
-                kooper->pos.y = sp24;
-                kooper->pos.z = sp28;
+            kooper->jumpVelocity -= kooper->jumpScale;
+            playerStatus->position.y += kooper->jumpVelocity;
+            if (kooper->jumpVelocity < 0.0f) {
+                if (!ShellTossKickFalling) {
+                    ShellTossKickFalling = TRUE;
+                    suggest_player_anim_allow_backward(ANIM_Mario1_Fall);
+                }
+            }
 
-                kooper->planarFlyDist += kooper->moveSpeed;
-                func_8003D660(kooper, 1);
-                kooper->moveSpeed -= 6.0;
+            posX = playerStatus->position.x;
+            posY = (playerStatus->position.y + playerStatus->colliderHeight / 2) - kooper->jumpVelocity;
+            posZ = playerStatus->position.z;
+            testLength = hitLength = playerStatus->colliderHeight / 2;
 
+            if ((npc_raycast_up(COLLISION_CHANNEL_10000, &posX, &posY, &posZ, &hitLength)) && (hitLength < testLength)) {
+                collisionStatus->currentCeiling = NpcHitQueryColliderID;
+                playerStatus->position.y = posY - playerStatus->colliderHeight;
+                kooper_vertical_hit_interactable_entity(kooper);
+            }
+
+            if (!(kooper->jumpVelocity > 0.0f) && (playerStatus->position.y < kooper->moveToPos.z)) {
+                D_802BEC5C = 0;
+                kooper->flags &= ~NPC_FLAG_IGNORE_PLAYER_COLLISION;
+                partnerActionStatus->actingPartner = PARTNER_KOOPER;
+                partnerActionStatus->partnerActionState = PARTNER_ACTION_KOOPER_TOSS;
+                kooper->rotation.z = 0.0f;
+                kooper->planarFlyDist = 0.0f;
+                kooper->moveSpeed = 8.0f;
+                kooper->currentAnim = ANIM_WorldKooper_SpinShell;
+                ShellTossHitboxState = SHELL_TOSS_HITBOX_ENABLED;
+                fx_damage_stars(3, kooper->pos.x, kooper->pos.y + kooper->collisionHeight, kooper->pos.z,
+                        sin_deg(playerStatus->targetYaw), -1.0f, -cos_deg(playerStatus->targetYaw), 3);
+                start_bounce_b();
+
+                if (ShellTossControlsPlayer) {
+                    enable_player_input();
+                    ShellTossControlsPlayer = FALSE;
+                }
+
+                script->USE_STATE = SHELL_TOSS_STATE_KICK;
+                ShellTossKickFalling = FALSE;
+                gCameras[CAM_DEFAULT].moveFlags |= CAMERA_MOVE_IGNORE_PLAYER_Y;
+                sfx_play_sound_at_npc(SOUND_283, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                sfx_play_sound_at_npc(SOUND_284, SOUND_SPACE_MODE_0, NPC_PARTNER);
+            }
+            break;
+
+        case SHELL_TOSS_STATE_KICK:
+            if (playerStatus->actionState == ACTION_STATE_HIT_FIRE
+             || playerStatus->actionState == ACTION_STATE_KNOCKBACK
+            ) {
+                script->USE_STATE = SHELL_TOSS_STATE_FINISH;
+                break;
+            }
+
+            // check the forward collision for kooper
+            #define TEST_COLLISION_AT_ANGLE(testAngle) \
+                ( \
+                posX = kooper->pos.x, \
+                posY = kooper->pos.y, \
+                posZ = kooper->pos.z, \
+                npc_test_move_taller_with_slipping(COLLISION_CHANNEL_8000, \
+                    &posX, &posY, &posZ, kooper->moveSpeed, testAngle,  \
+                    kooper->collisionHeight, kooper->collisionRadius / 2) \
+                )
+
+            if (TEST_COLLISION_AT_ANGLE(kooper->yaw - 20.0f)) {
+                if (!kooper_lateral_hit_interactable_entity(kooper)) {
+                    sfx_play_sound_at_npc(SOUND_IMMUNE, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                }
+
+                fx_damage_stars(3, kooper->pos.x, kooper->pos.y + kooper->collisionHeight, kooper->pos.z,
+                        sin_deg(kooper->yaw), -1.0f, -cos_deg(kooper->yaw), 1);
+                sfx_play_sound_at_npc(SOUND_0, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                script->USE_STATE = SHELL_TOSS_STATE_RETURN;
+                break;
+            }
+
+            if (TEST_COLLISION_AT_ANGLE(kooper->yaw + 20.0f)) {
+                if (!kooper_lateral_hit_interactable_entity(kooper)) {
+                    sfx_play_sound_at_npc(SOUND_IMMUNE, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                }
+
+                fx_damage_stars(3, kooper->pos.x, kooper->pos.y + kooper->collisionHeight, kooper->pos.z,
+                        sin_deg(kooper->yaw), -1.0f, -cos_deg(kooper->yaw), 1);
+                sfx_play_sound_at_npc(SOUND_0, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                script->USE_STATE = SHELL_TOSS_STATE_RETURN;
+                break;
+            }
+
+             if (TEST_COLLISION_AT_ANGLE(kooper->yaw)) {
+                if (!kooper_lateral_hit_interactable_entity(kooper)) {
+                    sfx_play_sound_at_npc(SOUND_IMMUNE, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                }
+
+                fx_damage_stars(3, kooper->pos.x, kooper->pos.y + kooper->collisionHeight, kooper->pos.z,
+                        sin_deg(kooper->yaw), -1.0f, -cos_deg(kooper->yaw), 1);
+                sfx_play_sound_at_npc(SOUND_0, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                script->USE_STATE = SHELL_TOSS_STATE_RETURN;
+                break;
+            }
+            
+            kooper->pos.x = posX;
+            kooper->pos.y = posY;
+            kooper->pos.z = posZ;
+            kooper->planarFlyDist += kooper->moveSpeed;
+            spawn_surface_effects(kooper, SURFACE_INTERACT_RUN);
+
+            kooper->moveSpeed += 2.0;
+            if (kooper->moveSpeed > 14.0) {
+                kooper->moveSpeed = 14.0f;
+            }
+
+            if (!(npc_try_snap_to_ground(kooper, 6.0f) || playerStatus->flags & (PS_FLAG_JUMPING | PS_FLAG_FALLING))) {
+                kooper->pos.y += (playerStatus->position.y - kooper->pos.y) / 10.0f;
+            }
+
+            npc_do_other_npc_collision(kooper);
+
+            if ((kooper->flags & NPC_FLAG_COLLIDING_WITH_NPC)) {
+                script->USE_STATE = SHELL_TOSS_STATE_RETURN;
+                kooper->moveSpeed = 0.0f;
+                sfx_play_sound_at_npc(SOUND_0, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                break;
+            }
+
+            if (kooper_check_for_item_collision(kooper)) {
+                sfx_play_sound_at_npc(SOUND_286, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                fx_damage_stars(3, kooper->pos.x, kooper->pos.y + kooper->collisionHeight, kooper->pos.z,
+                    sin_deg(kooper->yaw), -1.0f, -cos_deg(kooper->yaw), 1);
+                sfx_play_sound_at_npc(SOUND_0, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                script->USE_STATE = SHELL_TOSS_STATE_PICKUP;
+                KooperShellTossHoldTime = 8;
+                kooper->moveSpeed -= 4.0;
                 if (kooper->moveSpeed < 0.01) {
                     kooper->moveSpeed = 0.01f;
                     kooper->planarFlyDist += 1.0;
                 }
-
-                if (D_802BEC50 == 0) {
-                    script->functionTemp[0] = 7;
-                }
-                D_802BEC50--;
-                break;
-
-            case 5:
-                if (D_802BEC50 != 0) {
-                    D_802BEC50--;
-                } else {
-                    script->functionTemp[0] = 7;
-                }
-                break;
-            }
-
-        if (script->functionTemp[0] == 7) {
-            kooper->flags |= NPC_FLAG_IGNORE_PLAYER_COLLISION;
-            //TODO: make if statement less bad
-            if (((u8)playerStatus->actionState - 0x15) < 2U) {
-                script->functionTemp[0] = 0;
+            } else if (ShellTossHitboxState == SHELL_TOSS_HITBOX_HIT_ENEMY) {
+                sfx_play_sound_at_npc(SOUND_0, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                script->USE_STATE = SHELL_TOSS_STATE_HOLD;
+                KooperShellTossHoldTime = 30;
+                kooper->moveSpeed = 0.0f;
             } else {
-                temp2 = atan2(D_802BEC70, D_802BEC78, kooper->pos.x, kooper->pos.z);
-                kooper->yaw = temp2 + (get_clamped_angle_diff(kooper->yaw, temp2) * 0.125f);
-                npc_move_heading(kooper, -kooper->moveSpeed, kooper->yaw);
-                kooper->planarFlyDist -= kooper->moveSpeed;
-                func_8003D660(kooper, 1);
-                kooper->moveSpeed += 4.0/3.0;
-
-                if (kooper->moveSpeed > 14.0) {
-                    kooper->moveSpeed = 14.0f;
-                }
-
-                if (func_800397E8(kooper, 6.0f) == 0) {
-                    kooper->pos.y += (playerStatus->position.y - kooper->pos.y) / 10.0f;
-                }
-
-                sp20 = kooper->pos.x;
-                sp24 = kooper->pos.y;
-                sp28 = kooper->pos.z;
-
-                if (npc_test_move_taller_with_slipping(0x8000, &sp20, &sp24, &sp28, kooper->moveSpeed,
-                                                       clamp_angle(kooper->yaw + 180.0f), kooper->collisionHeight,
-                                                       kooper->collisionRadius) != 0) {
-                    kooper->pos.x = sp20;
-                    kooper->pos.y = sp24;
-                    kooper->pos.z = sp28;
-                    sfx_play_sound_at_npc(SOUND_IMMUNE, SOUND_SPACE_MODE_0, NPC_PARTNER);
-                    temp_f20_3 = sin_deg(kooper->yaw + 180.0f);
-                    fx_damage_stars(3, kooper->pos.x, kooper->pos.y + kooper->collisionHeight, kooper->pos.z,
-                            temp_f20_3, -1.0f, -cos_deg(kooper->yaw + 180.0f), 1);
-                    script->functionTemp[0] = 0;
-                } else {
-                    if (D_802BEC6C != 0) {
-                        itemGrabbed = get_item_entity(D_802BEC68);
-                        sp20 = kooper->pos.x;
-                        sp24 = kooper->pos.y + 8.0f;
-                        sp28 = kooper->pos.z;
-
-                        clamp = clamp_angle(playerStatus->targetYaw - ((D_802BEC58) ? 90.0f : -90.0f));
-
-                        add_vec2D_polar(&sp20, &sp28, 4.0f, clamp);
-                        itemGrabbed->position.x = sp20;
-                        itemGrabbed->position.y = sp24;
-                        itemGrabbed->position.z = sp28;
-                    }
-
-                    if (kooper->planarFlyDist + 15.0f < kooper->moveSpeed) {
-                        script->functionTemp[0] = 0;
-                    } else if (kooper->planarFlyDist + 15.0f < 35.0f) {
-                        kooper->moveSpeed -= 4.0;
-                        if (kooper->moveSpeed < 4.0) {
-                            kooper->moveSpeed = 4.0;
-                        }
+                if (kooper->planarFlyDist > 140.0f) {
+                    label2:
+                    script->USE_STATE = SHELL_TOSS_STATE_RETURN;
+                    kooper->moveSpeed = 0.0f;
+                    sfx_play_sound_at_npc(SOUND_0, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                } else if (kooper->planarFlyDist > 105.0f) {
+                    kooper->moveSpeed -= 4.0;
+                    if (kooper->moveSpeed < 0.01) {
+                        kooper->moveSpeed = 0.01f;
+                        kooper->planarFlyDist += 1.0;
                     }
                 }
+            }    
+            break;
+
+        case SHELL_TOSS_STATE_PICKUP:
+            posX = kooper->pos.x;
+            posY = kooper->pos.y;
+            posZ = kooper->pos.z;
+
+            npc_test_move_taller_with_slipping(COLLISION_CHANNEL_8000,
+                &posX, &posY, &posZ, kooper->moveSpeed, kooper->yaw,
+                kooper->collisionHeight, ( kooper->collisionRadius / 2));
+                
+            kooper->pos.x = posX;
+            kooper->pos.y = posY;
+            kooper->pos.z = posZ;
+
+            kooper->planarFlyDist += kooper->moveSpeed;
+            spawn_surface_effects(kooper, SURFACE_INTERACT_RUN);
+            kooper->moveSpeed -= 6.0;
+
+            if (kooper->moveSpeed < 0.01) {
+                kooper->moveSpeed = 0.01f;
+                kooper->planarFlyDist += 1.0;
             }
+
+            if (KooperShellTossHoldTime == 0) {
+                script->USE_STATE = SHELL_TOSS_STATE_RETURN;
+            }
+            KooperShellTossHoldTime--;
+            break;
+
+        case SHELL_TOSS_STATE_HOLD:
+            if (KooperShellTossHoldTime != 0) {
+                KooperShellTossHoldTime--;
+            } else {
+                script->USE_STATE = SHELL_TOSS_STATE_RETURN;
+            }
+            break;
         }
 
-        if (script->functionTemp[0] == 0) {
-            if (D_802BEC64 != 0) {
-                enable_player_input();
-                D_802BEC64 = 0;
+    if (script->USE_STATE == SHELL_TOSS_STATE_RETURN) {
+        kooper->flags |= NPC_FLAG_IGNORE_PLAYER_COLLISION;
+        if (playerStatus->actionState == ACTION_STATE_HIT_FIRE
+            || playerStatus->actionState == ACTION_STATE_KNOCKBACK
+        ) {
+            script->USE_STATE = SHELL_TOSS_STATE_FINISH;
+        } else {
+            angleToStartPos = atan2(ShellTossPosX, ShellTossPosZ, kooper->pos.x, kooper->pos.z);
+            kooper->yaw = angleToStartPos + get_clamped_angle_diff(kooper->yaw, angleToStartPos) * 0.125f;
+            npc_move_heading(kooper, -kooper->moveSpeed, kooper->yaw);
+            kooper->planarFlyDist -= kooper->moveSpeed;
+            spawn_surface_effects(kooper, SURFACE_INTERACT_RUN);
+            kooper->moveSpeed += 4.0/3.0;
+
+            if (kooper->moveSpeed > 14.0) {
+                kooper->moveSpeed = 14.0f;
             }
 
-            D_802BEB40_31CB60 = 0;
-            kooper->flags |= NPC_FLAG_IGNORE_PLAYER_COLLISION;
-            kooper->flags &= ~(NPC_FLAG_JUMPING | NPC_FLAG_IGNORE_WORLD_COLLISION);
-            partnerActionStatus->actingPartner = PARTNER_NONE;
-            partnerActionStatus->partnerActionState = PARTNER_ACTION_NONE;
-            kooper->jumpVelocity = 0.0f;
-            kooper->collisionHeight = 24;
-            kooper->currentAnim = ANIM_WorldKooper_Walk;
-            sfx_stop_sound(SOUND_284);
-            disable_npc_blur(kooper);
-
-            if (D_802BEC6C != 0) {
-                func_801341B0(D_802BEC68);
-                D_802BEC6C = 0;
+            if (npc_try_snap_to_ground(kooper, 6.0f) == 0) {
+                kooper->pos.y += (playerStatus->position.y - kooper->pos.y) / 10.0f;
             }
 
-            D_802BEC54 = 0;
-            partner_clear_player_tracking(kooper);
-            return ApiStatus_DONE2;
+            posX = kooper->pos.x;
+            posY = kooper->pos.y;
+            posZ = kooper->pos.z;
+
+            if (npc_test_move_taller_with_slipping(COLLISION_CHANNEL_8000,
+                &posX, &posY, &posZ, kooper->moveSpeed, clamp_angle(kooper->yaw + 180.0f),
+                kooper->collisionHeight, kooper->collisionRadius)
+            ) {
+                kooper->pos.x = posX;
+                kooper->pos.y = posY;
+                kooper->pos.z = posZ;
+                sfx_play_sound_at_npc(SOUND_IMMUNE, SOUND_SPACE_MODE_0, NPC_PARTNER);
+                testLength = sin_deg(kooper->yaw + 180.0f);
+                fx_damage_stars(3, kooper->pos.x, kooper->pos.y + kooper->collisionHeight, kooper->pos.z,
+                        testLength, -1.0f, -cos_deg(kooper->yaw + 180.0f), 1);
+                script->USE_STATE = SHELL_TOSS_STATE_FINISH;
+            } else {
+                if (KooperHasItem) {
+                    heldItem = get_item_entity(KooperHeldItemIdx);
+                    posX = kooper->pos.x;
+                    posY = kooper->pos.y + 8.0f;
+                    posZ = kooper->pos.z;
+
+                    moveAngle = clamp_angle(playerStatus->targetYaw - (ShellTossPlayerFacingLeft ? 90.0f : -90.0f));
+
+                    add_vec2D_polar(&posX, &posZ, 4.0f, moveAngle);
+                    heldItem->position.x = posX;
+                    heldItem->position.y = posY;
+                    heldItem->position.z = posZ;
+                }
+
+                if (kooper->planarFlyDist + 15.0f < kooper->moveSpeed) {
+                    script->USE_STATE = SHELL_TOSS_STATE_FINISH;
+                } else if (kooper->planarFlyDist + 15.0f < 35.0f) {
+                    kooper->moveSpeed -= 4.0;
+                    if (kooper->moveSpeed < 4.0) {
+                        kooper->moveSpeed = 4.0;
+                    }
+                }
+            }
         }
     }
+
+    if (script->USE_STATE == SHELL_TOSS_STATE_FINISH) {
+        if (ShellTossControlsPlayer) {
+            enable_player_input();
+            ShellTossControlsPlayer = FALSE;
+        }
+
+        ShellTossHitboxState = SHELL_TOSS_HITBOX_DISABLED;
+        kooper->flags |= NPC_FLAG_IGNORE_PLAYER_COLLISION;
+        kooper->flags &= ~(NPC_FLAG_JUMPING | NPC_FLAG_IGNORE_WORLD_COLLISION);
+        partnerActionStatus->actingPartner = PARTNER_NONE;
+        partnerActionStatus->partnerActionState = PARTNER_ACTION_NONE;
+        kooper->jumpVelocity = 0.0f;
+        kooper->collisionHeight = 24;
+        kooper->currentAnim = ANIM_WorldKooper_Walk;
+        sfx_stop_sound(SOUND_284);
+        disable_npc_blur(kooper);
+
+        if (KooperHasItem) {
+            auto_collect_item_entity(KooperHeldItemIdx);
+            KooperHasItem = FALSE;
+        }
+
+        KooperTriggeredBattle = FALSE;
+        partner_clear_player_tracking(kooper);
+        return ApiStatus_DONE2;
+    }
+
     return ApiStatus_BLOCK;
 }
 
-EvtScript world_kooper_use_ability = {
-    EVT_CALL(func_802BD638_31B658)
+EvtScript EVS_KooperUseAbility = {
+    EVT_CALL(KooperUseAbility)
     EVT_RETURN
     EVT_END
 };
 
-ApiStatus KooperPutAway(Evt* script, s32 isInitialCall) {
+API_CALLABLE(KooperPutAway) {
     Npc* kooper = script->owner2.npc;
 
     if (isInitialCall) {
@@ -609,7 +650,7 @@ ApiStatus KooperPutAway(Evt* script, s32 isInitialCall) {
     return partner_put_away(kooper) ? ApiStatus_DONE1 : ApiStatus_BLOCK;
 }
 
-EvtScript world_kooper_put_away = {
+EvtScript EVS_KooperPutAway = {
     EVT_CALL(KooperPutAway)
     EVT_RETURN
     EVT_END
@@ -625,10 +666,10 @@ s32 world_kooper_test_first_strike(Npc* kooper, Npc* enemy) {
     f32 kooperCollHeight;
     f32 enemyCollRadius;
     f32 kooperCollRadius;
-    f32 arctan;
-    f32 dist;
+    f32 angleToEnemy;
+    f32 distToEnemy;
 
-    if (D_802BEB40_31CB60 != 0) {
+    if (ShellTossHitboxState != SHELL_TOSS_HITBOX_DISABLED) {
         enemyX = enemy->pos.x;
         enemyY = enemy->pos.y;
         enemyZ = enemy->pos.z;
@@ -643,16 +684,16 @@ s32 world_kooper_test_first_strike(Npc* kooper, Npc* enemy) {
         kooperCollHeight = kooper->collisionHeight;
         kooperCollRadius = kooper->collisionRadius * 0.8;
 
-        arctan = atan2(enemyX, enemyZ, kooperX, kooperZ);
-        dist = dist2D(enemyX, enemyZ, kooperX, kooperZ);
+        angleToEnemy = atan2(enemyX, enemyZ, kooperX, kooperZ);
+        distToEnemy = dist2D(enemyX, enemyZ, kooperX, kooperZ);
 
         xTemp = kooper->pos.x;
         yTemp = kooper->pos.y;
         zTemp = kooper->pos.z;
 
-        if (npc_test_move_taller_with_slipping(0, &xTemp, &yTemp, &zTemp, dist, arctan, kooperCollHeight,
-                                                 kooperCollRadius + enemyCollRadius))
-        {
+        if (npc_test_move_taller_with_slipping(0, &xTemp, &yTemp, &zTemp, distToEnemy, angleToEnemy,
+            kooperCollHeight, kooperCollRadius + enemyCollRadius)
+        ) {
             return FALSE;
         }
 
@@ -666,10 +707,10 @@ s32 world_kooper_test_first_strike(Npc* kooper, Npc* enemy) {
 
         kooperX = enemyX - kooperX;
         kooperZ = enemyZ - kooperZ;
-        dist = SQ(kooperX) + SQ(kooperZ);
+        distToEnemy = SQ(kooperX) + SQ(kooperZ);
 
-        if (!(SQ(kooperCollRadius) + SQ(enemyCollRadius) <= dist)) {
-            D_802BEB40_31CB60 = 2;
+        if (!(SQ(kooperCollRadius) + SQ(enemyCollRadius) <= distToEnemy)) {
+            ShellTossHitboxState = SHELL_TOSS_HITBOX_HIT_ENEMY;
             return TRUE;
         }
     }
@@ -679,19 +720,19 @@ s32 world_kooper_test_first_strike(Npc* kooper, Npc* enemy) {
 void world_kooper_pre_battle(Npc* kooper) {
     PlayerStatus* playerStatus = &gPlayerStatus;
     PartnerActionStatus* kooperActionStatus = &gPartnerActionStatus;
-    D_802BEC54 = 0;
+    KooperTriggeredBattle = FALSE;
 
     if (kooperActionStatus->partnerActionState != PARTNER_ACTION_NONE) {
-        if (kooperActionStatus->partnerActionState == PARTNER_ACTION_KOOPER_2) {
-            D_802BEC54 = 1;
+        if (kooperActionStatus->partnerActionState == PARTNER_ACTION_KOOPER_TOSS) {
+            KooperTriggeredBattle = TRUE;
         }
 
-        if (D_802BEC64) {
+        if (ShellTossControlsPlayer) {
             enable_player_input();
-            D_802BEC64 = 0;
+            ShellTossControlsPlayer = FALSE;
         }
 
-        D_802BEB40_31CB60 = 0;
+        ShellTossHitboxState = SHELL_TOSS_HITBOX_DISABLED;
         playerStatus->flags &= ~PS_FLAG_JUMPING;
 
         kooper->jumpVelocity = 0.0f;
@@ -699,7 +740,7 @@ void world_kooper_pre_battle(Npc* kooper) {
         kooper->flags &= ~NPC_FLAG_IGNORE_WORLD_COLLISION;
 
         sfx_stop_sound(SOUND_284);
-        set_action_state(0);
+        set_action_state(ACTION_STATE_IDLE);
         partner_clear_player_tracking(kooper);
         disable_npc_blur(kooper);
 
@@ -709,7 +750,7 @@ void world_kooper_pre_battle(Npc* kooper) {
 }
 
 void world_kooper_post_battle(Npc* npc) {
-    if (D_802BEC54) {
+    if (KooperTriggeredBattle) {
         partner_clear_player_tracking(npc);
         partner_use_ability();
     }
diff --git a/src/world/partner/kooper.h b/src/world/partner/kooper.h
index 4ac3c86f5b..f156bdf523 100644
--- a/src/world/partner/kooper.h
+++ b/src/world/partner/kooper.h
@@ -9,9 +9,9 @@ s32 world_kooper_test_first_strike(Npc*, Npc*);
 void world_kooper_pre_battle(Npc*);
 void world_kooper_post_battle(Npc*);
 
-extern EvtScript world_kooper_take_out;
-extern EvtScript world_kooper_update;
-extern EvtScript world_kooper_use_ability;
-extern EvtScript world_kooper_put_away;
+extern EvtScript EVS_WorldKooperTakeOut;
+extern EvtScript EVS_WorldKooperUpdate;
+extern EvtScript EVS_KooperUseAbility;
+extern EvtScript EVS_KooperPutAway;
 
 #endif
diff --git a/src/world/partner/lakilester.c b/src/world/partner/lakilester.c
index 0838bb1d93..0903d54496 100644
--- a/src/world/partner/lakilester.c
+++ b/src/world/partner/lakilester.c
@@ -438,7 +438,7 @@ void func_802BDDD8_321928(Npc* npc) {
             npc->pos.z += (z - npc->pos.z) / 5.0f;
         }
 
-        func_8003D660(npc, 1);
+        spawn_surface_effects(npc, SURFACE_INTERACT_RUN);
 
     } else {
         yaw = 90.0f;
@@ -679,7 +679,7 @@ ApiStatus func_802BE724_322274(Evt* script, s32 isInitialCall) {
             npc->flags |= (NPC_FLAG_TOUCHES_GROUND | NPC_FLAG_IGNORE_PLAYER_COLLISION);
             set_action_state(ACTION_STATE_RIDE);
             D_802BFF0C = 1;
-            func_800EF4E0();
+            partner_force_player_flip_done();
             npc->moveToPos.x = playerStatus->position.x;
             npc->moveToPos.y = playerStatus->position.y;
             npc->moveToPos.z = playerStatus->position.z;
diff --git a/src/world/partner/parakarry.c b/src/world/partner/parakarry.c
index 8053790a3d..932525f252 100644
--- a/src/world/partner/parakarry.c
+++ b/src/world/partner/parakarry.c
@@ -242,7 +242,7 @@ ApiStatus func_802BD660_319BD0(Evt* evt, s32 isInitialCall) {
                 parakarry->flags |= NPC_FLAG_IGNORE_WORLD_COLLISION | NPC_FLAG_8;
                 partnerActionStatus->actingPartner = PARTNER_PARAKARRY;
                 partnerActionStatus->partnerActionState = PARTNER_ACTION_PARAKARRY_HOVER;
-                D_802BEBBC = func_800EF4E0();
+                D_802BEBBC = partner_force_player_flip_done();
                 enable_npc_blur(parakarry);
                 parakarry->yaw = atan2(parakarry->pos.x, parakarry->pos.z, playerStatus->position.x, playerStatus->position.z);
                 parakarry->duration = 4;
@@ -489,7 +489,7 @@ ApiStatus func_802BD660_319BD0(Evt* evt, s32 isInitialCall) {
                                                         parakarry->pos.y = playerStatus->position.y + 32.0f,
                                                         y = parakarry->pos.y,
                                                         parakarry->pos.y = playerStatus->position.y,
-                                                        func_8003D660(parakarry, 0),
+                                                        spawn_surface_effects(parakarry, SURFACE_INTERACT_WALK),
                                                         parakarry->pos.y = y, (!tempConditional))) {
                                                 if (!phys_adjust_cam_on_landing()) {
                                                     gCameras[0].moveFlags &= ~CAMERA_MOVE_FLAG_2;
diff --git a/src/world/partner/watt.c b/src/world/partner/watt.c
index 01e8f1e15d..32e8454b85 100644
--- a/src/world/partner/watt.c
+++ b/src/world/partner/watt.c
@@ -303,7 +303,7 @@ ApiStatus func_802BD754_31D2C4(Evt* script, s32 isInitialCall) {
                 gGameStatusPtr->keepUsingPartnerOnMapChange = 0;
                 partnerActionStatus->partnerActionState = PARTNER_ACTION_USE;
                 partnerActionStatus->actingPartner = PARTNER_WATT;
-                func_800EF4E0();
+                partner_force_player_flip_done();
                 npc->moveToPos.x = playerStatus->position.x;
                 npc->moveToPos.y = playerStatus->position.y + 5.0f;
                 npc->moveToPos.z = playerStatus->position.z;
@@ -365,7 +365,7 @@ ApiStatus func_802BD754_31D2C4(Evt* script, s32 isInitialCall) {
         D_802BE304 = 20;
         npc_set_palswap_mode_A(npc, 0);
         if (!(playerStatus->flags & PS_FLAG_HIT_FIRE)) {
-            set_action_state(0);
+            set_action_state(ACTION_STATE_IDLE);
         }
         return ApiStatus_DONE1;
     }
diff --git a/src/world/partners.c b/src/world/partners.c
index 6e0a845a46..2b15830426 100644
--- a/src/world/partners.c
+++ b/src/world/partners.c
@@ -194,10 +194,10 @@ WorldPartner wPartners[12] = {
         .dmaDest = &world_partner_kooper_VRAM,
         .isFlying = FALSE,
         .init = world_kooper_init,
-        .takeOut = &world_kooper_take_out,
-        .update = &world_kooper_update,
-        .useAbility = &world_kooper_use_ability,
-        .putAway = &world_kooper_put_away,
+        .takeOut = &EVS_WorldKooperTakeOut,
+        .update = &EVS_WorldKooperUpdate,
+        .useAbility = &EVS_KooperUseAbility,
+        .putAway = &EVS_KooperPutAway,
         .idle = ANIM_WorldKooper_Idle,
         .testFirstStrike = world_kooper_test_first_strike,
         .canUseAbility = partner_is_idle,
@@ -574,7 +574,7 @@ s32 partner_is_flying(void) {
 }
 
 void func_800EA5B8(Npc* partner) {
-    partner->flags &= ~(NPC_FLAG_COLLIDING_WITH_NPC | NPC_FLAG_COLLDING_FORWARD_WITH_WORLD | NPC_FLAG_COLLDING_WITH_WORLD | NPC_FLAG_FALLING |
+    partner->flags &= ~(NPC_FLAG_COLLIDING_WITH_NPC | NPC_FLAG_COLLDING_FORWARD_WITH_WORLD | NPC_FLAG_COLLDING_WITH_WORLD | NPC_FLAG_GROUNDED |
                           NPC_FLAG_JUMPING);
 }
 
@@ -1252,7 +1252,7 @@ void partner_walking_follow_player(Npc* partner) {
                 partner->moveSpeed = 4.0f;
             }
             partner->currentAnim = gPartnerAnimations[wCurrentPartnerId].run;
-            if (!(partner->flags & NPC_FLAG_FALLING)) {
+            if (!(partner->flags & NPC_FLAG_GROUNDED)) {
                 partner->currentAnim = gPartnerAnimations[wCurrentPartnerId].fall;
             }
             while (TRUE) {
@@ -1300,28 +1300,23 @@ void partner_walking_follow_player(Npc* partner) {
                         break;
                     }
 
-                    if ((partner->flags & NPC_FLAG_FALLING) && currentSnapshot->isJumping) {
+                    if ((partner->flags & NPC_FLAG_GROUNDED) && currentSnapshot->isJumping) {
                         wPartnerFollowState = 1;
                         break;
                     }
                 }
             }
 
-            if (!(partner->flags & NPC_FLAG_FALLING)) {
+            if (!(partner->flags & NPC_FLAG_GROUNDED)) {
                 partner->moveSpeed *= 0.5f;
             }
             partner->yaw = yaw;
             npc_move_heading(partner, partner->moveSpeed, partner->yaw);
-            if (partner->moveSpeed < 4.0) {
-                var_a1 = 0;
-            } else {
-                var_a1 = 1;
-            }
-            func_8003D660(partner, var_a1);
+            spawn_surface_effects(partner, (partner->moveSpeed < 4.0) ? SURFACE_INTERACT_WALK : SURFACE_INTERACT_RUN);
             surfaceType = get_collider_flags(partner->currentFloor);
             if (surfaceType == SURFACE_TYPE_SPIKES ||
                 surfaceType == SURFACE_TYPE_LAVA ||
-                (partner->flags & (NPC_FLAG_FALLING | NPC_FLAG_COLLDING_FORWARD_WITH_WORLD)) == (NPC_FLAG_FALLING | NPC_FLAG_COLLDING_FORWARD_WITH_WORLD)) {
+                (partner->flags & (NPC_FLAG_GROUNDED | NPC_FLAG_COLLDING_FORWARD_WITH_WORLD)) == (NPC_FLAG_GROUNDED | NPC_FLAG_COLLDING_FORWARD_WITH_WORLD)) {
                 if (!func_800EA4B0(partner->currentWall)) {
                     D_8010CFBC++;
                     if (D_8010CFBC >= 40) {
@@ -1433,7 +1428,7 @@ void partner_walking_follow_player(Npc* partner) {
                         partner->jumpVelocity = 0.0f;
                         partner->pos.y = y;
                         partner->yaw = atan2(x, z, playerStatus->position.x, playerStatus->position.z);
-                        func_8003D660(partner, 2);
+                        spawn_surface_effects(partner, SURFACE_INTERACT_LAND);
                         wPartnerFollowState = 0;
                         distance = dist2D(partner->pos.x, partner->pos.z, partner->moveToPos.x, partner->moveToPos.z);
                         if (distance < 5.0) {
@@ -1509,12 +1504,7 @@ void partner_walking_follow_player(Npc* partner) {
                     }
                     partner->yaw = yaw;
                     npc_move_heading(partner, partner->moveSpeed, yaw);
-                    if (partner->moveSpeed < 4.0) {
-                        var_a1 = 0;
-                    } else {
-                        var_a1 = 1;
-                    }
-                    func_8003D660(partner, var_a1);
+                    spawn_surface_effects(partner, (partner->moveSpeed < 4.0) ? SURFACE_INTERACT_WALK : SURFACE_INTERACT_RUN);
                     distance = 1000.0f;
                     x = partner->pos.x;
                     z = partner->pos.z;
@@ -1633,12 +1623,7 @@ void partner_walking_follow_player(Npc* partner) {
                         partner->moveSpeed = wPartnerMoveSpeed;
                         partner->yaw = D_800F8034;
                         npc_move_heading(partner, partner->moveSpeed, partner->yaw);
-                        if (partner->moveSpeed < 4.0) {
-                            var_a1 = 0;
-                        } else {
-                            var_a1 = 1;
-                        }
-                        func_8003D660(partner, var_a1);
+                        spawn_surface_effects(partner, (partner->moveSpeed < 4.0) ? SURFACE_INTERACT_WALK : SURFACE_INTERACT_RUN);
                     } else {
                         partner_clear_player_tracking(partner);
                         partner->moveSpeed = 0.0f;
@@ -1663,7 +1648,7 @@ void partner_walking_follow_player(Npc* partner) {
             partner_move_to_goal(partner, FALSE);
             break;
         case 40:
-            if (partner->flags & NPC_FLAG_FALLING) {
+            if (partner->flags & NPC_FLAG_GROUNDED) {
                 if (func_800EA4B0(partner->currentFloor)) {
                     wPartnerFollowState = 50;
                     partner->currentAnim = gPartnerAnimations[wCurrentPartnerId].idle;
@@ -1699,7 +1684,7 @@ void partner_walking_follow_player(Npc* partner) {
                 partner->jumpVelocity = 0.0f;
                 partner->pos.y = y;
                 partner->yaw = atan2(x, z, playerStatus->position.x, playerStatus->position.z);
-                func_8003D660(partner, 2);
+                spawn_surface_effects(partner, SURFACE_INTERACT_LAND);
                 wPartnerFollowState = 50;
             }
             break;
@@ -2334,7 +2319,7 @@ s32 partner_get_out(Npc* partner) {
             partner->currentAnim = gPartnerAnimations[wCurrentPartnerId].jump;
             break;
         case 1:
-            if (partner->jumpVelocity < 0.0f && func_800397E8(partner, fabsf(partner->jumpVelocity))) {
+            if (partner->jumpVelocity < 0.0f && npc_try_snap_to_ground(partner, fabsf(partner->jumpVelocity))) {
                 wPartnerFollowState = 2;
                 break;
             }
@@ -2378,9 +2363,9 @@ s32 partner_get_out(Npc* partner) {
             partner->pos.x = partner->moveToPos.x;
             partner->pos.y = partner->moveToPos.y;
             partner->pos.z = partner->moveToPos.z;
-            if (partner->flags & 0x1000) {
+            if (partner->flags & NPC_FLAG_GROUNDED) {
                 if (!wPartner->isFlying) {
-                    func_8003D660(partner, 2);
+                    spawn_surface_effects(partner, SURFACE_INTERACT_LAND);
                 }
             }
             return TRUE;
@@ -2458,29 +2443,32 @@ void partner_clear_player_tracking(Npc* partner) {
     }
 }
 
-s32 func_800EF4E0(void) {
+// forces the player to complete a direction flip if they are currently performing one
+// the resulting camera-relative direction is returned as a boolean 'isFacingLeft'
+s32 partner_force_player_flip_done(void) {
     PlayerStatus* playerStatus = &gPlayerStatus;
     Camera* cameras = gCameras;
-    s32 ret;
+    s32 isFacingLeft;
 
     if (playerStatus->flipYaw[CAM_DEFAULT] == 0.0f) {
         if (!(playerStatus->spriteFacingAngle >= 90.0f) || !(playerStatus->spriteFacingAngle < 270.0f)) {
-            ret = 1;
+            isFacingLeft = TRUE;
             playerStatus->targetYaw = clamp_angle(cameras[CAM_DEFAULT].currentYaw - 90.0f);
         } else {
+            isFacingLeft = FALSE;
             playerStatus->targetYaw = clamp_angle(cameras[CAM_DEFAULT].currentYaw + 90.0f);
-            ret = 0;
         }
     } else if (get_clamped_angle_diff(cameras[CAM_DEFAULT].currentYaw, playerStatus->targetYaw) < 0.0f) {
-        ret = 1;
+        isFacingLeft = TRUE;
         playerStatus->targetYaw = clamp_angle(cameras[CAM_DEFAULT].currentYaw - 90.0f);
+        
     } else {
-        ret = 0;
+        isFacingLeft = FALSE;
         playerStatus->targetYaw = clamp_angle(cameras[CAM_DEFAULT].currentYaw + 90.0f);
     }
 
     playerStatus->currentYaw = playerStatus->targetYaw;
-    return ret;
+    return isFacingLeft;
 }
 
 void partner_enable_input(void) {
@@ -2548,7 +2536,7 @@ void partner_move_to_goal(Npc* partner, s32 isFlying) {
             if (wPartnerMoveTime != 0) {
                 wPartnerMoveTime--;
                 if (!isFlying) {
-                    if (!(partner->flags & NPC_FLAG_FALLING)) {
+                    if (!(partner->flags & NPC_FLAG_GROUNDED)) {
                         partner->pos.y = playerStatus->position.y;
                     }
                     if (partner->jumpVelocity != 0.0f) {
@@ -2592,12 +2580,7 @@ void partner_move_to_goal(Npc* partner, s32 isFlying) {
                     npc_move_heading(partner, partner->moveSpeed, partner->yaw);
                 }
 
-                if (partner->moveSpeed < 4.0) {
-                    var_a1 = 0;
-                } else {
-                    var_a1 = 1;
-                }
-                func_8003D660(partner, var_a1);
+                spawn_surface_effects(partner, (partner->moveSpeed < 4.0) ? SURFACE_INTERACT_WALK : SURFACE_INTERACT_RUN);
             } else {
                 partner->flags &= ~NPC_FLAG_IGNORE_WORLD_COLLISION;
                 partner->currentAnim = gPartnerAnimations[wCurrentPartnerId].idle;
diff --git a/src/world/partners.h b/src/world/partners.h
index b4092b9c61..b30f17f8d1 100644
--- a/src/world/partners.h
+++ b/src/world/partners.h
@@ -35,7 +35,7 @@ s32 partner_use_ability(void);
 void partner_do_player_collision(Npc* partner);
 void partner_walking_follow_player(Npc* partner);
 s32 func_800EA52C(s32);
-s32 func_800EF4E0(void);
+s32 partner_force_player_flip_done(void);
 void partner_suspend_ability_script(void);
 void partner_resume_ability_script(void);
 void partner_enable_input(void);
diff --git a/tools/ignored_funcs.txt b/tools/ignored_funcs.txt
index e672e378f2..27b7534911 100644
--- a/tools/ignored_funcs.txt
+++ b/tools/ignored_funcs.txt
@@ -252,7 +252,7 @@ dead_dma_copy = 0x8002AA2C;
 dead_get_entity_by_index = 0x80118BB0;
 dead_cos_rad = 0x8002B4C0;
 dead_fx_sun = 0x80077BD0;
-dead_func_8003D660 = 0x80041080;
+dead_spawn_surface_effects = 0x80041080;
 dead_set_max_SP = 0x800F1D9C;
 dead_sync_status_menu = 0x800F1730;
 dead_get_npc_by_index = 0x8003C43C;
diff --git a/tools/splat_ext/pm_charset.py b/tools/splat_ext/pm_charset.py
index 86e38f67e5..2af7a93feb 100644
--- a/tools/splat_ext/pm_charset.py
+++ b/tools/splat_ext/pm_charset.py
@@ -17,6 +17,31 @@ def next_8(n):
     else:
         return n
 
+def get_palette_idx(charset_name, char_id):
+    pal_id = 0
+    if charset_name == "standard":
+        if char_id == 0x98:
+            pal_id = 0x10
+        elif char_id == 0x99:
+            pal_id = 0x11
+        elif char_id == 0x9A:
+            pal_id = 0x15
+        elif char_id == 0x9B:
+            pal_id = 0x15
+        elif char_id == 0x9C:
+            pal_id = 0x15
+        elif char_id == 0x9D:
+            pal_id = 0x13
+        elif char_id == 0x9E:
+            pal_id = 0x13
+        elif char_id == 0x9F:
+            pal_id = 0x13
+        elif char_id == 0xA0:
+            pal_id = 0x13
+        elif char_id == 0xA1:
+            pal_id = 0x12
+    return pal_id
+
 class N64SegPm_charset(N64Segment):
     def scan(self, rom_bytes):
         data = rom_bytes[self.rom_start:self.rom_end]
@@ -39,7 +64,8 @@ class N64SegPm_charset(N64Segment):
         fs_dir.mkdir(parents=True, exist_ok=True)
 
         for i, raster in enumerate(self.rasters):
-            palette = self.sibling.palettes[0]
+            pal_idx = get_palette_idx(self.name, i)
+            palette = self.sibling.palettes[pal_idx]
 
             w = png.Writer(self.width, self.height, palette=palette)
             with open(fs_dir / f"{i:02X}.png", "wb") as f:
diff --git a/ver/us/symbol_addrs.txt b/ver/us/symbol_addrs.txt
index 2ce251cc35..62c3b23a9c 100644
--- a/ver/us/symbol_addrs.txt
+++ b/ver/us/symbol_addrs.txt
@@ -253,8 +253,8 @@ get_npc_by_index = 0x80038ADC; // type:func rom:0x13EDC
 npc_do_world_collision = 0x80038AFC; // type:func rom:0x13EFC
 npc_do_other_npc_collision = 0x8003900C; // type:func rom:0x1440C
 npc_do_player_collision = 0x800392D8; // type:func rom:0x146D8
-npc_do_gravity = 0x80039688; // type:func rom:0x14A88
-func_800397E8 = 0x800397E8; // type:func rom:0x14BE8
+npc_try_apply_gravity = 0x80039688; // type:func rom:0x14A88
+npc_try_snap_to_ground = 0x800397E8; // type:func rom:0x14BE8
 update_npcs = 0x80039930; // type:func rom:0x14D30
 npc_get_render_yaw = 0x80039DA4; // type:func rom:0x151A4
 appendGfx_npc = 0x80039FD0; // type:func rom:0x153D0
@@ -288,7 +288,7 @@ npc_draw_palswap_mode_4 = 0x8003BED8; // type:func rom:0x172D8
 npc_set_decoration = 0x8003C3D8; // type:func rom:0x177D8
 npc_remove_decoration = 0x8003C428; // type:func rom:0x17828
 npc_update_decorations = 0x8003C444; // type:func rom:0x17844
-npc__remove_decoration = 0x8003C53C; // type:func rom:0x1793C
+npc_remove_decoration_impl = 0x8003C53C; // type:func rom:0x1793C
 npc_reset_current_decoration = 0x8003C61C; // type:func rom:0x17A1C
 npc_update_decoration_none = 0x8003C658; // type:func rom:0x17A58
 npc_remove_decoration_none = 0x8003C660; // type:func rom:0x17A60
@@ -311,13 +311,13 @@ npc_find_standing_on_entity = 0x8003D1D4; // type:func rom:0x185D4
 npc_get_collider_below = 0x8003D2F8; // type:func rom:0x186F8
 func_8003D3BC = 0x8003D3BC; // type:func rom:0x187BC
 func_8003D624 = 0x8003D624; // type:func rom:0x18A24
-func_8003D660 = 0x8003D660; // type:func rom:0x18A60
-func_8003D788 = 0x8003D788; // type:func rom:0x18B88
-func_8003DA38 = 0x8003DA38; // type:func rom:0x18E38
-func_8003DC38 = 0x8003DC38; // type:func rom:0x19038
-func_8003DFA0 = 0x8003DFA0; // type:func rom:0x193A0
-func_8003E0D4 = 0x8003E0D4; // type:func rom:0x194D4
-func_8003E1D0 = 0x8003E1D0; // type:func rom:0x195D0
+spawn_surface_effects = 0x8003D660; // type:func rom:0x18A60
+spawn_default_surface_effects = 0x8003D788; // type:func rom:0x18B88
+spawn_flower_surface_effects = 0x8003DA38; // type:func rom:0x18E38
+spawn_cloud_surface_effects = 0x8003DC38; // type:func rom:0x19038
+spawn_snow_surface_effects = 0x8003DFA0; // type:func rom:0x193A0
+spawn_hedge_surface_effects = 0x8003E0D4; // type:func rom:0x194D4
+spawn_water_surface_effects = 0x8003E1D0; // type:func rom:0x195D0
 COPY_set_defeated = 0x8003E2E0; // type:func rom:0x196E0
 init_encounter_status = 0x8003E338; // type:func rom:0x19738
 clear_encounter_status = 0x8003E400; // type:func rom:0x19800
@@ -3012,7 +3012,7 @@ func_800EF3E4 = 0x800EF3E4; // type:func rom:0x88894
 func_800EF414 = 0x800EF414; // type:func rom:0x888C4
 func_800EF43C = 0x800EF43C; // type:func rom:0x888EC
 partner_clear_player_tracking = 0x800EF45C; // type:func rom:0x8890C
-func_800EF4E0 = 0x800EF4E0; // type:func rom:0x88990
+partner_force_player_flip_done = 0x800EF4E0; // type:func rom:0x88990
 partner_enable_input = 0x800EF600; // type:func rom:0x88AB0
 partner_disable_input = 0x800EF628; // type:func rom:0x88AD8
 partner_do_player_collision = 0x800EF640; // type:func rom:0x88AF0
@@ -3932,7 +3932,7 @@ delete_entity = 0x801106D0; // type:func rom:0xA6DD0
 delete_entity_and_unload_data = 0x80110790; // type:func rom:0xA6E90
 _delete_shadow = 0x8011085C; // type:func rom:0xA6F5C
 entity_get_collision_flags = 0x801108B8; // type:func rom:0xA6FB8
-entity_interacts_with_current_partner = 0x801109DC; // type:func rom:0xA70DC
+entity_try_partner_interaction_trigger = 0x801109DC; // type:func rom:0xA70DC
 test_player_entity_aabb = 0x80110AAC; // type:func rom:0xA71AC
 is_player_action_state = 0x80110BB0; // type:func rom:0xA72B0
 entity_set_render_script = 0x80110BCC; // type:func rom:0xA72CC
@@ -4277,7 +4277,7 @@ test_item_player_collision = 0x80133B0C; // type:func rom:0xCA20C
 test_item_entity_position = 0x80133FC8; // type:func rom:0xCA6C8
 set_item_entity_flags = 0x80134148; // type:func rom:0xCA848
 clear_item_entity_flags = 0x80134188; // type:func rom:0xCA888
-func_801341B0 = 0x801341B0; // type:func rom:0xCA8B0
+auto_collect_item_entity = 0x801341B0; // type:func rom:0xCA8B0
 is_picking_up_item = 0x801341E8; // type:func rom:0xCA8E8
 set_item_entity_position = 0x8013420C; // type:func rom:0xCA90C
 set_current_item_entity_render_group = 0x80134230; // type:func rom:0xCA930
@@ -7744,30 +7744,30 @@ D_802BEB10_31B080 = 0x802BEB10; // type:data rom:0x31B080
 D_802BEB98_31B108 = 0x802BEB98; // type:data rom:0x31B108
 D_802BEBA0_31B110 = 0x802BEBA0; // type:data rom:0x31B110
 D_802BEBA8_31B118 = 0x802BEBA8; // type:data rom:0x31B118
-func_802BD100_31B120 = 0x802BD100; // type:func rom:0x31B120
+kooper_lateral_hit_interactable_entity = 0x802BD100; // type:func rom:0x31B120
 D_802BEBB4 = 0x802BEBB4; // type:data rom:0x31B124
 D_802BEBB8 = 0x802BEBB8; // type:data rom:0x31B128
 D_802BEBBC = 0x802BEBBC; // type:data rom:0x31B12C
 D_802BEBC0_31CBE0 = 0x802BEBC0; // type:data rom:0x31B130
 D_802BEBC4 = 0x802BEBC4; // type:data rom:0x31B134
 ParakarryTweesterPhysics = 0x802BEBC8; // type:data rom:0x31B138
-func_802BD144_31B164 = 0x802BD144; // type:func rom:0x31B164
-func_802BD17C_31B19C = 0x802BD17C; // type:func rom:0x31B19C
+kooper_vertical_hit_interactable_entity = 0x802BD144; // type:func rom:0x31B164
+kooper_check_for_item_collision = 0x802BD17C; // type:func rom:0x31B19C
 world_kooper_init = 0x802BD200; // type:func rom:0x31B220
 KooperTakeOut = 0x802BD228; // type:func rom:0x31B248
 KooperUpdate = 0x802BD260; // type:func rom:0x31B280
-func_802BD5F4_31B614 = 0x802BD5F4; // type:func rom:0x31B614
-func_802BD638_31B658 = 0x802BD638; // type:func rom:0x31B658
+kooper_try_cancel_tweester = 0x802BD5F4; // type:func rom:0x31B614
+KooperUseAbility = 0x802BD638; // type:func rom:0x31B658
 KooperPutAway = 0x802BE7E0; // type:func rom:0x31C800
 world_kooper_test_first_strike = 0x802BE818; // type:func rom:0x31C838
 world_kooper_pre_battle = 0x802BEA24; // type:func rom:0x31CA44
 world_kooper_post_battle = 0x802BEB10; // type:func rom:0x31CB30
-D_802BEB40_31CB60 = 0x802BEB40; // type:data rom:0x31CB60
-world_kooper_take_out = 0x802BEB44; // type:data rom:0x31CB64
+ShellTossHitboxState = 0x802BEB40; // type:data rom:0x31CB60
+EVS_WorldKooperTakeOut = 0x802BEB44; // type:data rom:0x31CB64
 KooperTweesterPhysicsPtr = 0x802BEB60; // type:data rom:0x31CB80
-world_kooper_update = 0x802BEB64; // type:data rom:0x31CB84
-world_kooper_use_ability = 0x802BEB80; // type:data rom:0x31CBA0
-world_kooper_put_away = 0x802BEB9C; // type:data rom:0x31CBBC
+EVS_WorldKooperUpdate = 0x802BEB64; // type:data rom:0x31CB84
+EVS_KooperUseAbility = 0x802BEB80; // type:data rom:0x31CBA0
+EVS_KooperPutAway = 0x802BEB9C; // type:data rom:0x31CBBC
 D_802BEC18_31CC38 = 0x802BEC18; // type:data rom:0x31CC38
 D_802BEC20_31CC40 = 0x802BEC20; // type:data rom:0x31CC40
 D_802BEC28_31CC48 = 0x802BEC28; // type:data rom:0x31CC48
@@ -7775,16 +7775,16 @@ D_802BEC30_31CC50 = 0x802BEC30; // type:data rom:0x31CC50
 D_802BEC38_31CC58 = 0x802BEC38; // type:data rom:0x31CC58
 D_802BEC40_31CC60 = 0x802BEC40; // type:data rom:0x31CC60
 func_802BD100_31CC70 = 0x802BD100; // type:func rom:0x31CC70
-D_802BEC54 = 0x802BEC54; // type:data rom:0x31CC74
-D_802BEC58 = 0x802BEC58; // type:data rom:0x31CC78
+KooperTriggeredBattle = 0x802BEC54; // type:data rom:0x31CC74
+ShellTossPlayerFacingLeft = 0x802BEC58; // type:data rom:0x31CC78
 D_802BEC5C = 0x802BEC5C; // type:data rom:0x31CC7C
-D_802BEC60 = 0x802BEC60; // type:data rom:0x31CC80
-D_802BEC64 = 0x802BEC64; // type:data rom:0x31CC84
-D_802BEC68 = 0x802BEC68; // type:data rom:0x31CC88
+ShellTossKickFalling = 0x802BEC60; // type:data rom:0x31CC80
+ShellTossControlsPlayer = 0x802BEC64; // type:data rom:0x31CC84
+KooperHeldItemIdx = 0x802BEC68; // type:data rom:0x31CC88
 D_802BEC6C = 0x802BEC6C; // type:data rom:0x31CC8C
 D_802BEC70 = 0x802BEC70; // type:data rom:0x31CC90
-D_802BEC74 = 0x802BEC74; // type:data rom:0x31CC94
-D_802BEC78 = 0x802BEC78; // type:data rom:0x31CC98
+ShellTossPosY = 0x802BEC74; // type:data rom:0x31CC94
+ShellTossPosZ = 0x802BEC78; // type:data rom:0x31CC98
 D_802BEC7C = 0x802BEC7C; // type:data rom:0x31CC9C
 KooperTweesterPhysics = 0x802BEC80; // type:data rom:0x31CCA0
 world_watt_dispose_static_effect = 0x802BD180; // type:func rom:0x31CCF0
@@ -27140,7 +27140,7 @@ D_802BE300 = 0x802BE300; // type:data
 D_802BE920 = 0x802BE920; // type:data
 D_802BEBB0 = 0x802BEBB0; // type:data
 D_802BEBC0 = 0x802BEBC0; // type:data
-D_802BEC50 = 0x802BEC50; // type:data
+KooperShellTossHoldTime = 0x802BEC50; // type:data
 OriginalPlayerY = 0x802BFEE0; // type:data
 D_802BFEF0 = 0x802BFEF0; // type:data
 D_802BFEFC = 0x802BFEFC; // type:data
diff --git a/ver/us/undefined_syms.txt b/ver/us/undefined_syms.txt
index d6f85ae156..02564368bb 100644
--- a/ver/us/undefined_syms.txt
+++ b/ver/us/undefined_syms.txt
@@ -148,7 +148,7 @@ dead_get_npc_unsafe = get_npc_unsafe + 0x39D0;
 dead_get_npc_safe = get_npc_safe + 0x39EC;
 dead_disable_npc_shadow = disable_npc_shadow + 0x39EC;
 dead_set_npc_yaw = set_npc_yaw + 0x3A10;
-dead_func_8003D660 = func_8003D660 + 0x3A20;
+dead_spawn_surface_effects = spawn_surface_effects + 0x3A20;
 dead_get_enemy = get_enemy + 0x3E0C;
 dead_SetEncounterStatusFlags = SetEncounterStatusFlags + 0x40A0;
 dead_IsStartingConversation = IsStartingConversation + 0x40A0;