Very Cool!
I've only got a couple of suggestions:
1) Some of the sound effects, Goomba's footsteps, for example, repeat too often and too loudly, I'd suggest getting a cyble of three or four very similar sound effects instead of one over and over and turn down the volume a bit.
2) It looks a little awkward when Goomba uses his feet as his hands, the goombas the in the games (most notably, Mario Party series) manipulate and hold things much like Homestar Runner from the internet series of the same name, looks like telekeineses with a limit of arm's lenth. It would smooth out the action a bit, and leave his feet free for running and crazy acrobatics.