Valve will release Alien Swarm - a four-player, co-operative, top-down shooter - on Steam for free today. The PC game is an entirely new version of an old mod for Unreal Tournament 2004. The ...

Wow, here's a Friday surprise. Valve just announced that it's releasing a full version of Alien Swarm, a co-operative shooter based on an old Unreal Tournament 2004 mod, next week. And it’s free. Keep ...