Left 4 Dead is the kind of game that comes around once every four or five years that makes you seriously look at what "multiplayer" is and how it can be improved upon. With titles like Gears of War 2 and Call of Duty: World at War offering their Horde and Nazi Zombie modes, it would seem that Turtle Rock and Valve have essentially created something that contains concepts from both of those while offering a longer and more satisfying experience than the two combined. The game has a few faults, but none of these faults keep you from trying to take out the zombie apocalypse time and time again.