Aliens is an arcade game based loosely on the 1986 movie Aliens. You and a friend play female Marines and you must explore and destroy all aliens who have taken over a now abandoned space settlement LV426 Acheron. If you can find any survivors try to rescue them. As well as your normal gun there are other weapons that can be used to help you. A Caterpillar P-5000 can also be found and used.

Aliens is mainly a side view horizontal shooter where the screen scrolls as you move from left to right. Some parts of the game require you to look behind the hero firing into the screen as aliens come towards from the distance as well as moving in other directions like in a lift. You can also be driving into the screen trying to shoot aliens.

The multinational conglomerate Weyland-Yutani Corporation has lost contact with its mining colony, Hadley's Hope, in LV426 Acheron. In response, the Colonial Marine troops of the USS Sulaco decide to send their team to investigate. The marines soon discover that the place is infested by an unknown parasitic alien life form and that the Hadley's Hope crew was either exterminated or used as hosts to breed the creatures' next offspring.