Probably the best community made boss I have seen. Everything from the opening cutscene to the boss itself was well made and the fact that it featured my favourite track in the game didn't hurt either.
very nice take on the original lbp2 boss (negativitron), my only suggestion would be to do a little more with the piano itself.. let it do little riffs etc.. but besides that.. not bad.. not bad at all!
LOVE THE BOSS MUSIC!!!!! You should make it a prize! Please?