I beat the game and got at least a gold on all the side missions.  I had a blast the entire time.  A lot of people give the game flak for it's graphics, but there is A LOT going on in the game.  At one point I was flying a chopper shooting rockets all over the place while there were 3 tanks on the ground fighting about 4-5 hunters, explosions were all over the place and there were tons of pedestrians/infected/military personnel running around and the framerate was solid (Xbox 360 version).  Considering all that, the models and textures don't bother me so much.  I mean, while it lacks graphic "punch," it's still not a bad looking game.