Anyone who loves music games should check this out. It has a very quirky style that works well with the music. The game is HIGHLY addictive. You say to yourself that you want to try it one more time, then you look up to see 3 hours have gone by. It's a very well balanced game. I might be going out on a limb here, but I think it may be better than Guitar Hero (and I LOVE Guitar Hero).
I downloaded the demo at EB and it was pretty great. If I don't get the game for Christmas, I'll pick it up soon after. It's unfortunate that the demo is only about three minutes long, but I suppose the whole idea is to leave them (meaning "me") wanting more.