diff --git a/.clang-format b/.clang-format
deleted file mode 100644
index c7b900f060..0000000000
--- a/.clang-format
+++ /dev/null
@@ -1,23 +0,0 @@
-IndentWidth: 4
-Language: Cpp
-UseTab: Never
-ColumnLimit: 120
-PointerAlignment: Left
-BreakBeforeBraces: Attach
-SpaceAfterCStyleCast: false
-Cpp11BracedListStyle: false
-IndentCaseLabels: true
-BinPackArguments: true
-BinPackParameters: true
-AlignAfterOpenBracket: Align
-AlignOperands: true
-BreakBeforeTernaryOperators: true
-BreakBeforeBinaryOperators: None
-AllowShortBlocksOnASingleLine: true
-AllowShortIfStatementsOnASingleLine: false
-AllowShortLoopsOnASingleLine: false
-AllowShortCaseLabelsOnASingleLine: false
-AllowShortFunctionsOnASingleLine: false
-AlignEscapedNewlines: Left
-AlignTrailingComments: true
-SortIncludes: false
diff --git a/.clang-tidy b/.clang-tidy
index 4022a3f68a..d1f01520b0 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -1,5 +1,2 @@
-Checks: '-*,readability-braces-around-statements'
-WarningsAsErrors: ''
-HeaderFilterRegex: '(src|include)\/.*\.h$'
-FormatStyle: 'file'
-CheckOptions:
+Checks: '-*,clang-analyzer-core.*,clang-analyzer-deadcode.*,readability-*,-readability-magic-numbers,-readability-else-after-return,-readability-named-parameter,-readability-braces-around-statements,-clang-diagnostic-error'
+HeaderFilterRegex: '(src|include)\/.*\.h'
diff --git a/.github/workflows/lint.yaml b/.github/workflows/lint.yaml
new file mode 100644
index 0000000000..17f1c8b168
--- /dev/null
+++ b/.github/workflows/lint.yaml
@@ -0,0 +1,39 @@
+name: Lint
+on:
+  push:
+    paths:
+      - 'src/*'
+      - 'include/*'
+  pull_request:
+    paths:
+      - 'src/*'
+      - 'include/*'
+
+jobs:
+  build:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - run: ./install.sh
+
+      # lint files changed by the push/pr
+      - id: files
+        uses: trilom/file-changes-action@v1.2.4
+        with:
+          output: ' '
+        continue-on-error: true # see jitterbit/get-changed-files#7
+      - run: ./format.sh ${{ steps.files.outputs.files}}
+
+      # fail if any files were changed by ./format.sh
+      - id: files_formatted
+        uses: jackton1/find-changed-files@v1.1
+        with:
+          files: src, include
+
+      - name: Fail if any files reformatted
+        if: steps.files_formatted.outputs.files_changed == 'true'
+        run: |
+          git diff
+          exit 1
diff --git a/.vscode/settings.json b/.vscode/settings.json
index c5dfc84c80..571f956be5 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -3,4 +3,5 @@
     "editor.insertSpaces": true,
     "files.eol": "\n",
     "files.insertFinalNewline": true,
+    "editor.rulers": [120],
 }
diff --git a/format.sh b/format.sh
index 90de3119e4..5f631f128b 100755
--- a/format.sh
+++ b/format.sh
@@ -1,26 +1,34 @@
-FORMAT_OPTS="-i -style=file"
-TIDY_OPTS="-p . --fix --fix-errors"
-COMPILER_OPTS="-fno-builtin -std=gnu90 -Iinclude -Isrc -D_LANGUAGE_C -DNON_MATCHING"
+COMPILER_OPTS="-fno-builtin -std=gnu89 -Iinclude -Isrc -D_LANGUAGE_C"
 
 shopt -s globstar
 
+FILES="src/**/*.c include/*.h"
 if (( $# > 0 )); then
-    echo "Formatting file(s) $*"
-    echo "Running clang-format..."
-    clang-format ${FORMAT_OPTS} "$@"
-    echo "Running clang-tidy..."
-    clang-tidy ${TIDY_OPTS} "$@" -- ${COMPILER_OPTS} &> /dev/null
-    echo "Adding missing final new lines..."
-    sed -i -e '$a\' "$@"
-    echo "Done formatting file(s) $*"
+    # only process .c and .h files
+    FILES=$(echo "$@" | sed 's/ /\n/g' | grep '.[ch]$')
+fi
+
+if [[ -z $FILES ]]; then
+    echo "no .c or .h files specified"
     exit
 fi
 
-echo "Formatting C files. This will take a bit"
-echo "Running clang-format..."
-clang-format ${FORMAT_OPTS} src/**/*.c
-echo "Running clang-tidy..."
-clang-tidy ${TIDY_OPTS} src/**/*.c -- ${COMPILER_OPTS} &> /dev/null
-echo "Adding missing final new lines..."
-find src/ -type f -name "*.c" -exec sed -i -e '$a\' {} \;
-echo "Done formatting all files."
+# format
+astyle ${FILES} \
+    --formatted --suffix=none \
+    --lineend=linux \
+    --convert-tabs \
+    --max-code-length=120 \
+    --min-conditional-indent=1 \
+    --style=attach \
+    --align-pointer=type --align-reference=name \
+    --indent-switches \
+    --indent-labels \
+    --pad-oper --pad-comma --pad-header --unpad-paren \
+    --attach-return-type \
+
+# add newline at eof
+find ${FILES} -exec sed -i -e '$a\' {} \;
+
+# lint
+clang-tidy -p . ${FILES} -- ${COMPILER_OPTS}
diff --git a/include/variables.h b/include/variables.h
index 2051fff0a7..d3602c9944 100644
--- a/include/variables.h
+++ b/include/variables.h
@@ -48,7 +48,7 @@ extern s16 D_8010CD10;
 extern s16 D_8010CD12;
 extern s32 D_801595A0;
 extern char gCloudyFlowerFieldsBg[]; // "fla_bg"
-extern char gSunnyFlowerFieldsBg[]; // "flb_bg"
+extern char gSunnyFlowerFieldsBg[];  // "flb_bg"
 extern BackgroundHeader gBackgroundImage;
 extern s8 D_8014F12F;
 
diff --git a/install.sh b/install.sh
index 96f300b767..89d0498d3c 100755
--- a/install.sh
+++ b/install.sh
@@ -8,8 +8,8 @@ if command -v apt-install &> /dev/null; then
 
     if [[ $1 == "--extra" ]]; then
         echo "Installing extra"
-        sudo apt install -y python3 python3-pip clang-tidy clang-format
-        python3 -m pip install stringcase
+        sudo apt install -y python3 python3-pip clang-tidy astyle || exit 1
+        python3 -m pip install stringcase || exit 1
     fi
 
     echo "Done"
@@ -48,7 +48,7 @@ if command -v pacman &> /dev/null; then
 
     if [[ $1 == "--extra" ]]; then
         echo "Installing extra"
-        sudo pacman -S --noconfirm --needed python python-pip clang || exit 1
+        sudo pacman -S --noconfirm --needed python python-pip clang astyle || exit 1
         python3 -m pip install stringcase || exit 1
     fi