Small mistakes, but pure beautyness.
Well, I gotta say, this is one of the best made flashes I've ever seen. Good job, man.
Personally, I like the idea of a musicated fight. I wanted to to one myself. :P Anyways, the tweening and graphics' animations are good done, and this adds many points to the rating.
There are, of course, silly mistakes that kept you from the ten, but they're all stetycal. For example, some animations are to slow and it really makes it look bad. Plus, in some sprites, there are traces of white lines from its original background. Did you separate the colors or traced the bitmap? If you did the first, I recommend you to do the second. Works like this: create a new symbol. Import and drag from the library the sprite sheet. Then go to Modify>Bit Map>Trace Bitmap (second option). In the options, put: one, one pixel, the first option (the first drop-down option) and the first option (the second drop-down). Wait, select and erase the background color. It should look better.
I hope I could help. Keep those submissions up! =D