[From the back of the case]:
Four survivors in an epic struggle fighting hordes of swarming zombies. Can you survive the zombie apocalypse?
Winner of many awards, including Best of E3 from Game Informer and more, Left 4 Dead is an intense new action game from Valve, creators of Half-Life, Counter-Strike, Portal, and Team Fortress.
Single player, co-op and multiplayer modes are powered by the "AI Director" which changes the zombies, effects, and more to create a different experience every time you play.
Features 100s of zombies, 20 new maps, 10 new weapons and four sprawling "Movie Campaigns." Plus, Versus Mode—play as the Boss Infected!