Warhammer 40.000: Space Marine is a third-person shooter set in the setting of Warhammer 40.000. The player assumes the character of Captain Titus, a member of the Space Marines’ elite Ultra Marines. His mission: to repel the Orc invasion on the industrial planet Graia. A super weapon is stored there, and the Orcs must not take it. He must also contend with Chaos Marines and other alien races.
The gameplay is straightforward: navigate through the levels, generally with two other Marines, and fight the enemy hordes. Titus has a variety of ranged and melee weaponry at his disposal, but melee fighting is his primary focus. Combo attacks are accomplished by pressing the relevant buttons at the right time, as in most comparable games. In addition, when he has accumulated enough wrath through slaying adversaries, he can unleash powerful assaults. Titus must also tackle rail shooter sequences, and he occasionally receives a jet pack and a more open-level design. No cover system and a mix of regeneration shield and health may be replenished by conducting executions to account for the Space Marine class character.