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!
I thought the boss had a very good concept, but it kinda felt like it went from being ridiculously easy, to agonisingly hard. The orange pieces of sponge seemed to splat a bit too often for my liking, never the less it was a great level series full of visually stunning platforming and an original storyline. Good job guys!