Warhammer 40,000: Space Marine's co-op mode, dubbed "Exterminatus" is now available on the PlayStation 3 and PC for the lovely price of nothing.
The new mode will put a squad of four Space Marines against waves of aliens in a score-based battle. Players have the Tactician Marine, Devastator or Assault Marine class to chose from, each having their own set of weapons and perks to choose from.
Experience earned in this mode will go towards the player's multiplayer ranks as well as the co-op ranks. So it's all nice and connected.
Xbox 360 users will have to wait a little bit more as the mode will be going live soon.