Hey, pretty good
As a fan of Super Smash Bros, I'm glad to see someone submit a decent flash on it. Your animation was decent, and your graphics were good.
Much of the fighting was very cool, and the sfx were well used (Marth and Roy versus Bowser, and Cpt Falcon plotting with Ganon, as examples). The sound quality could be better, however. I presume you're recording with a mic from a TV; I'd suggest a more direct rip if you can.
As highlights go, I think Ness going all Children of the Damned was fitting and damned funny. Very strange, but funny still.
My big complaint is that there's no real background, (big white void, sorta dull) and a lot of the fighting is someone attacking someone from off screen and killing them. If you perhaps laid the characters in some sort of actual giant match on one of the maps and let the real chaos we know from the game show through, you'd have a better peice.
All in all, good stuff. I look forwards to seeing a sequal and further works. :)