Set in the middle of a zombie apocalypse, players start as a small group of survivors attempting to stay alive.

Initially released on December 28, 2007, via Mod DB page as a public beta (v1.0) and later re-released for Steam via Steamworks on October 8, 2008, as a free-to-play game.

At the start of each round, players can either choose to join the human team or volunteer to be the first zombie.

The catch is that when a human dies he will simply join the ranks of the undead, now ready to finish off his old living teammates.

Eventually, there will only be one survivor still standing if everything goes wrong, his back against the wall while facing the animated corpses of his former allies.