I really couldn't do any better, sadly.
Most of the point go to the effort, since you put a lot of time into this flash, and I could tell that it was a pain in the ass choreographing the fight sequence. The two things that bothered me was that the characters looked too basic, and also the intro was way too long, staring at a title screen and waiting for the characters to be introduced can wear on the brain a little.
The thing about introductions is:
MOre than half the people who use newgrounds are confined to a dialup modem, so they are already pissed off enough that they have to stare at a loading screen for a movie to load up, so throwing in a minute long introduction doesn't make it any easier.
But the action was smooth and fluid, and you seem to be good at animation. It's just that the actual drawing aspect needed to be fixed, and maybe you need to work on adding more detail. Overall, it wasn't bad.