Hmm, very mediocre
I thought this was pretty good because it was cool to see you use the different backgrounds. It reminded me back of my days when I played "Super Mario World" and I recognized this stuff. The downside is that the animation does need a little work. It did look like a lot of the things were just quickly superimposed in the flash. The funniest part might have been when Mario died and then immediately killed the flying koopa. The best use of graphics was probably Toad popping out of the bag.