This is a first-person shooter in which players engage in futuristic battles against invading aliens. Players use pistols, sniper rifles, machine guns, and rocket launchers to shoot and kill enemies during the constant and fast-paced battle. Firefights are highlighted by camera effects (e.g., blurring and screen shakes) and realistic sound effects, including screams of pain, gunfire, and explosions. Puffs of blood are emitted from injured aliens/humans, and blood is sometimes smeared on walls and on the ground. Some profanity (e.g., "bullsh*t," "a*shole," and "bastard") can be heard in the dialogue and radio chatter.