All the Latest Game Footage and Images from Alien Swarm Alien Swarm is a game and Source SDK release from a group of talented designers at Valve who were hired from the Mod community. Available free ...

Are you and your friend looking for free-to-play co-op fun? Then, try out the following fantastic games on Steam.

GameSpot may get a commission from retail offers. If you've been looking for an online co-op game with some Alien vibes, the upcoming top-down tactical shooter DarkSwarm might just tickle your fancy.