diff --git a/examples/demo/fog b/examples/demo/fog
new file mode 100644
index 0000000..8754e00
--- /dev/null
+++ b/examples/demo/fog
@@ -0,0 +1,28 @@
+(resetTransform)
+(clear)
+
+(def w (of (frame) :c))
+(def h (of (frame) :m ))
+
+(defn mouse-pos (pos))
+(defn prev-pos (pos))
+
+(defn update (e) (
+  (set mouse-pos :x (of e :x))
+  (set mouse-pos :y (of e :y))
+))
+
+(on "animate" '(
+  (stroke (line prev-pos mouse-pos) 4 "#fff")
+  (move w h)
+  (rotate 0.002)
+  (scale 0.998)
+  
+  (translate (frame) (pos (mul -1 w) (mul -1 h)))
+  (resetTransform)
+  (fill (frame) "#00000004")
+  (set prev-pos :x (of mouse-pos :x))
+  (set prev-pos :y (of mouse-pos :y))
+))
+
+(on "mouse-move" update)
\ No newline at end of file