It was released for Microsoft Windows, PlayStation 3 and Xbox 360 on September 6, 2011, in North America and September 9, 2011, in Europe. The game takes place in Games Workshop's Warhammer 40,000 universe and features the Ultramarines chapter. Titus is accompanied by the characters Sidonus and Leandros for most of the missions, though some missions are performed alone. The starting weapons include a combat knife and a pistol, though the player can acquire other weapons. The game's main antagonists are the Orks and the Forces of Chaos. The game's plot line involves the Forge World Graia that has been invaded by alien Orks. This done, Mira thanks the Space Marines and continues to help Titus however she can over the course of the game, amidst re-organizing the remaining Imperial Guard forces and attempting to hold the majority of the invading hordes at bay until the delayed reinforcement fleet arrives.