Overall a fantastic piece, but could be better
Okay, let's see...
Graphics - no problem. They're practically the same as the original movies. The styles and moves were well drawn out as well as the effects. Overall, impressive, but could've been better.
Style - Wow, classic characters of newgrounds battling it out on a huge melee game. Reminds me a lot of super smash bros, speaking of that... I wanna get SSB Brawl badly... =P
Sound - Excellent, but gets REALLY annoying sometimes. Good thing you have an option during pause to turn off the goddamn music tracks. It hurts my ears sometimes.
Characters: Okay, this is where I want to make a couple of suggestions. It's okay if the characters are knocked out when they lose, but for someone to DIE, like Pico's head falling off. It's funny, I've got to admit, but it makes it a bit contradictory, since he's dead he can't fight anymore.
Suggestions: You need to add a few more characters. Seriously. Some of the best characters on newgrounds are forgotten and I really want to see them fight, such as:
1. Blockhead (OH GOD, WHY DIDN'T YOU ADD HIM???)
2. Bitey (From Adam Philip's Brackenwood series
3. Protagonist of Krinkel's Madness series.
4. Xiao Xiao
5. Gary from Numa Numa
6. Foamy
Etc... as in, you lack quite a few famous character =D.