Very funny!
My recommendations:
1. A more detailed background such as cloudy and sunny (I understand time constraint).
2. A little bit of voice when he is about to fall.
3. When he grabs onto the branch, have it at an angle where we think it is still on the cliff, but isn't (because it snaps off immediately). What you currently have is an inconsistency - which is fine as it is, but the branch seemed to hold him up pretty well and then suddenly snap without us knowing.
Just some suggestions :)
Still great artwork, animation, and humorous plot.
+H+