I think it's because Killzone 2 had a sort of linear and mediocre SP campaign, where in Halo 3, you could approach objective from many difference scenerios(flying, warthog, 4wheeler, gunsablazin, ect).
Also, I think the MP in Halo 3 is about as close to perfect as a game has ever achieved.
The game was also a huge achievement, so early in the generation.
I'd say both games ended up with the scores they deserve. :P
I don't need your console war.
It feeds the rich while it buries the poor.
You're power hungry, spinnin' stories, and bein' graphics whores.
I don't need your console war.
NO NO, NO NO NO.







