diff --git a/rooms/Stage.lua b/rooms/Stage.lua
index 7f45d3d..471113f 100644
--- a/rooms/Stage.lua
+++ b/rooms/Stage.lua
@@ -24,6 +24,15 @@ function Stage:update(dt)
         end
     end
 
+    if input:pressed('left') then
+        for _, game_object in ipairs(self.area.game_objects) do
+            if game_object:is(Circle) then
+                ---@cast game_object Circle
+                if game_object.mode == "fill" then game_object.mode = "line" else game_object.mode = "fill" end
+            end
+        end
+    end
+
     self.timer:update(dt)
 end