The player controls a Colonial Marine moving from left to right across a series of levels. The marine can move, jump, and shoot in multiple directions using an 8-way joystick and two buttons. The player must eliminate all enemies on screen to progress, with a timer counting down. Weapons include a standard pulse rifle and limited power-ups. The game is known for its challenging difficulty and the need for precise shooting and dodging.

Keep moving to avoid enemy fire. Shoot in bursts to conserve ammunition. Use the environment to your advantage and learn enemy spawn patterns. The pulse rifle's grenade launcher is useful for clearing groups, but save it for tough enemies. Memorize level layouts to avoid being caught by aliens.