that was ace
you should break your tweens in half and do them in smaller steps so, for instance: when he bends over and his back leg goes up, it starts to bend, then shortens and then stretches out again. Put a keyframe in the middle of that tween and stretch the leg out. other than that this was great! maybe some sound effects would do this justice...
I guess you could call this a slight variation on an old idea, but even so, the timing was spot on.
P.S. Put a little bit more time into your pre-loader and the 'credits', doing that will really add to the quality.