To put this in perspective.
Halo got 9.5/10
Halo 2 got 9.7/10
PC Gamer gave it a 95%
By the way Bioshock box doesn't have Only on Xbox on it hint... hint...
Edit: Before you say it's because it's coming on PC too, check the boxes of Gears and Lost Planet.
-Tough, scary combat
-Perfect location design
-Stunning soundtrack and audio effects
-Endless variety of weaponry
Thanks to Blacksaber for the sig!