It’s two weeks after the zombie apocalypse; do you know where your fellow survivors are? If you want to stay alive, you’d better. Left 4 Dead, the newest survival/horror first-person shooter by Valve, brings a whole new meaning to cooperative game-play.

Left 4 Dead gives players the chance to step into the shoes of one of four survivors of a zombie infestation, while they try to help each other live through it. However, that’s about all the story you’ll get from the game – though how much story is needed for a zombie game is questionable.

L4D offers three main game modes, two of which are online multi-player modes: Campaign, Versus, and Single Player.

Of the three, Campaign mode is the meat of the game; you and up to three other players (any spots not filled by players are controlled by the computer) make your way through urban and rural areas while fighting off hordes of “Infected.”

There are four stages in Campaign mode, each with a few “Safe Room” checkpoints where players can heal, replenish ammo, and revive fallen survivors. Single Player mode is the same as Campaign except there are no other players.

Versus mode pits two teams of players against each other (four survivors and four infected) as the survivors try to make their way to the checkpoints and the infected try to stop them.

After a couple of hours, the game-play can become a bit repetitive. However, the game’s A.I. Director keeps the game fresh by randomizing most of the game elements, and adapting to your play-style

Where the game-play shines, however, is in its need for cooperation. If you wander too far from your fellow survivors, the zombies will find you, and you will die. Staying together and watching each other’s backs is the only way to survive.

While a little repetitive, Left 4 Dead is a fun game, particularly if you have someone to play alongside you. So lock and load, and watch out around that corner.