As players run and jump through side-scrolling levels, they use rifles, pistols, flamethrowers, and explosives to kill enemy soldiers and aliens (i.e., “xenomorphs”).

The frenetic battles are highlighted by realistic gunfire, explosions, and cries of pain; injured aliens emit green splashes of blood before collapsing to the ground. Some sequences also depict red blood spurts when human characters are killed (e.g., an alien bursting out of a man's chest; characters getting bitten by aliens).