Ok...
Round one
-Not very good. Jumpy animation with physics leaving more to be desired. Also not really that funny or random.
Round two
-Alright, still has the same problems as round one, but to a lesser extent. Good effort.
Round three
-Looks nice, but relies strongly on special effects, I can see, as the actual frame by frame stick animation within is rubbish. Definately getting there.
Round four
-Awesome animation. Yes, it is full of special effects, but there are some moments where I feel you've put some real effort into it. Great comic timing too, along with some actual randomness.