I can't speak for MP3, but after playing a review copy of Bioshock, it's killer. It's better than 'Gears,' and is as good, if not better, than Halo and Halo 2 on single player. It is a fresh look at the FPS genre, hence why it's so hot right now. And even on easy, it's not hard to unlock achievements.
I have been playing since Thursday evening - it's sweeeeet!!!!
And in Bioshock, you really don't need multiplayer. It's strong enough on single player as is. While having multi would be sweet, the game is big and I'm not sure if it could be set up later to be multi.







