The first level on the Sonic Heroes demo is damn fun. Almost the whole time its fast paced which is what a Sonic game is supposed to be. But the second level on the demo is kind of meh.
But yeah, I agree that the demo disk isn't as great as it was hyped to be (ie: Pre-Order MK and get this great demo disk!). *gasp* Jon has said something bad about Nintendo/Nintendo game

But I played the all the demo's and most are good.
But MK: DD is pretty good. I haven't had the chance to play Multi yet since I don't have enough friends over yet who can play the game with me.