Wow!
I am really impressed with game... this just goes to show you that Flash has awesome potential for really fun games, when people are willing to write the code and make the artwork, and put time into thier work.
It's like you were going for a Super Smash Bros. style game here, and you did a good job of it, without completely ripping off the idea
More characters, more moves, more levels... Tweak the engine for any bugs that are reported, and concentrate on adding content, if you plan to release an update to this submission.