diff --git a/.luacheckrc b/.luacheckrc
new file mode 100644
index 0000000..8badbca
--- /dev/null
+++ b/.luacheckrc
@@ -0,0 +1,30 @@
+-- .luacheckrc
+-- Configuration for luacheck
+--
+-- The CI lint step aborts on any warning, so both the project's own globals
+-- and the TIC-80 API functions this game calls have to be declared here.
+
+globals = {
+  -- the game's own globals
+  "Context",
+  "init_game",
+
+  -- TIC-80 callbacks and API
+  "TIC",
+  "btn",
+  "btnp",
+  "cls",
+  "exit",
+  "keyp",
+  "mget",
+  "mset",
+  "rect",
+  "rectb",
+  "spr",
+}
+
+-- The INPUT_KEY_* constants are a coherent set (LEFT/RIGHT/A/B/X/Y); some are
+-- not bound yet, and dropping them would leave gaps in the mapping.
+ignore = { "211/INPUT_KEY_.*" }
+
+std = "lua51" -- TIC-80 runs Lua 5.1
diff --git a/inc/system/system.main.lua b/inc/system/system.main.lua
index db93d45..bb52ac6 100644
--- a/inc/system/system.main.lua
+++ b/inc/system/system.main.lua
@@ -45,7 +45,7 @@ function init_game()
 end
 
 function TIC()
-  init_game() 
+  init_game()
 
   cls(Config.colors.black)
   local handler = STATE_HANDLERS[Context.active_window]
diff --git a/inc/system/system.ui.lua b/inc/system/system.ui.lua
index 879939f..2f6ffda 100644
--- a/inc/system/system.ui.lua
+++ b/inc/system/system.ui.lua
@@ -35,7 +35,7 @@ end
 function UI.word_wrap(text, max_chars_per_line)
     if text == nil then return {""} end
     local lines = {}
-    
+
     for input_line in (text .. "\n"):gmatch("(.-)\n") do
         local current_line = ""
         local words_in_line = 0
@@ -50,18 +50,18 @@ function UI.word_wrap(text, max_chars_per_line)
                 current_line = word
             end
         end
-        
+
         if words_in_line > 0 then
             table.insert(lines, current_line)
         else
             table.insert(lines, "")
         end
     end
-    
+
     if #lines == 0 then
         return {""}
     end
-    
+
     return lines
 end
 
diff --git a/inc/window/window.configuration.lua b/inc/window/window.configuration.lua
index b933959..ceb4805 100644
--- a/inc/window/window.configuration.lua
+++ b/inc/window/window.configuration.lua
@@ -39,15 +39,15 @@ function ConfigurationWindow.draw()
   for i, control in ipairs(ConfigurationWindow.controls) do
     local current_y = y_start + (i - 1) * 12
     local color = Config.colors.green
-    
+
     if control.type == "numeric_stepper" then
       local value = control.get()
       local label_text = control.label
       local value_text = string.format(control.format, value)
-      
+
       -- Calculate x position for right-aligned value
       local value_x = x_value_right_align - (#value_text * char_width)
-      
+
       if i == ConfigurationWindow.selected_control then
         color = Config.colors.item
         Print.text("<", x_start -8, current_y, color)
@@ -70,7 +70,7 @@ function ConfigurationWindow.draw()
       end
     end
   end
-  
+
   Print.text("Press B to go back", x_start, 120, Config.colors.light_grey)
 end
 
diff --git a/inc/window/window.intro.lua b/inc/window/window.intro.lua
index d18f3e2..cb0ea52 100644
--- a/inc/window/window.intro.lua
+++ b/inc/window/window.intro.lua
@@ -1,9 +1,9 @@
-function IntroWindow.draw() 
+function IntroWindow.draw()
   local x = (Config.screen.width - 132) / 2 -- Centered text
   Print.text(Context.intro.text, x, Context.intro.y, Config.colors.green)
 end
 
-function IntroWindow.update() 
+function IntroWindow.update()
   Context.intro.y = Context.intro.y - Context.intro.speed
 
   -- Count lines in intro text to determine when scrolling is done
diff --git a/inc/window/window.menu.lua b/inc/window/window.menu.lua
index bbf7765..33b7ff0 100644
--- a/inc/window/window.menu.lua
+++ b/inc/window/window.menu.lua
@@ -53,7 +53,7 @@ function MenuWindow.refresh_menu_items()
   table.insert(Context.menu_items, {label = "Load Game", action = MenuWindow.load_game})
   table.insert(Context.menu_items, {label = "Configuration", action = MenuWindow.configuration})
   table.insert(Context.menu_items, {label = "Exit", action = MenuWindow.exit})
-  
+
   Context.selected_menu_item = 1 -- Reset selection after refreshing
 end
 
diff --git a/inc/window/window.popup.lua b/inc/window/window.popup.lua
index f053bb7..3c08e15 100644
--- a/inc/window/window.popup.lua
+++ b/inc/window/window.popup.lua
@@ -52,7 +52,7 @@ function PopupWindow.update()
         selected_item.action()
       end
     end
-    
+
     if Input.menu_back() then
       GameWindow.set_state(WINDOW_GAME)
     end
@@ -92,7 +92,7 @@ function PopupWindow.draw()
     Print.text(line, 50, current_y, Config.colors.light_grey)
     current_y = current_y + 8 -- Move to the next line (8 pixels for default font height + padding)
   end
-  
+
   -- Adjust menu position based on the number of wrapped lines
   if not Context.dialog.showing_description then
     UI.draw_menu(Context.dialog.menu_items, Context.dialog.selected_menu_item, 50, current_y + 2)