Thank you for bringing up the other point I forgot: the story is god awful. It's so bad that you wouldn't know what going on unless you read the ****ing books.
The story has no main character. There are no leads as to who you're supposed to be, why you're fighting, not even what you're trying to do. They just hand you a gun and say 'go shoot stuff.' Oh, no, I'm sorry, they don't ask that, they hand you a gun and say 'find some ammo.' Seriously, what the hell? There's no uniqueness to the overall story, either, as it follows the generic 'human race is doomed by alien race' thing and then you make way for the ****ing Half Life 2 zombies.
It's bad enough that Microsoft flat out admits that the story is bad when they hire someone to write books as canon so you could have a freakin' clue as to what exactly was going on and who you are, and to fill the huge, unexplainable gap between Halo 1 and Halo 2; it was like half the script got thrown into the garbage. To make matters worse, any character development they chose to make happened with and only with the ARBITER. You know... the one with the BAD GUYS?!
As far as I can tell, Bungie's creativity, or lack thereof, will be completely obvious in Halo 3; people are hyping the game for a dramatic ending, but face it, this game is made by the same guys that made Halo 2, and there was NOTHING compelling in that title; they couldn't even make a worthwhile cliffhanger.
And believe me, the AI is nothing to brag about; nobody takes cover except for the elites, who seem to lose all sight of you once they hide, as you can just walk up to them and bash their heads open. I've even seen grunts and jackals fall off cliffs, humans run in front of vehicles, I've even seen respective enemies and allies throw their grenades against the ceiling or wall. TimeSplitters Future Perfect had better AI in the multiplayer.
Oh, and thank you for proving fanboys' loyalty to Bungie; they change everything that made Halo 3 look remotely next gen, everyone is all in a fit about it, as they hoped that the campaign would at least look better than the multiplayer, but then Bungie says 'we think it looks better this way,' and everyone's like 'oh, okay.' It pains me that people are paying $60-$120 for this.