Available free of charge, the game thrusts players into an epic bug hunt featuring a unique blend of co-op play and squad-level tactics. With your friends, form a squad of four distinct IAF Marine classes. Plan your attack using an unlockable arsenal of weapons with countless loadout configurations against a wide variety of aliens. Blaze your way through an overrun, off-world colony, eradicating the alien infestation in environments ranging from the icy planet's surface, to a subterranean lava-flooded mining facility. * Tactical, 4 player co-op action game with a top-down perspective * Complete game code and mod tools * Unlock persistent items by gaining levels * Over 40 weapons and equipment with countless loadout configurations * 4 unique classes and 8 unique characters * Matchmaking, Steam Cloud, Steam Stats * 64 achievements * Tile-based map generation tool * Powered by Source and Steam