This game's only major flaw is that its AMAZING multiplayer shadows the game's single player campaign.
The multiplayer is worth $100 alone. The level system adds some interest to it; it gives you some motivation and with 550 levels (55 levels and you can repeat the levels up to ten times). There are a few problems like sometimes the teams are unbalanced (a few times everybody on one team had over 10 kills while nobody on the other team had more than 5 kills). Also in the free-for-alls the starting points are so close together you can take three steps forward and be shot from behind even on bigger maps. A few times I've been killed by an airstrike, respawned, and killed by the same airstrike. These problems aren't much of a problem.