The player assumes the role of Ellen Ripley and can use a variety of weapons and equipment including the motion scanner, welder, pulse rifle (both bullets and grenades), and flamethrower. Additional ammunition and medkits are available in each level. Unlike the other games based on the film, this one utilizes a mission structure. After approaching one of numerous central computer terminals, the player accepts a mission from a list and then must perform the task described (such as rescuing prisoners, repairing fuse boxes, destroying alien eggs, welding doors shut, etc). Once all missions in a level are completed, a password is provided and the game advances to the next stage.
Unlike the film, the game features numerous aliens including facehuggers, chestbursters, warriors, and an adult alien queen. There are also multiple non-canonical "mother aliens" — egg-layers who are smaller than the queen. At the end of the game, the alien queen is pushed into molten lead by a piston and Ripley, as in the movie, commits suicide to prevent the Weyland-Yutani corporation from getting their hands on the alien incubating inside her.