The Colonial Marine faction had the Medic, Scout, Soldier, and Heavy Weapons classes.

Scenarios were played in one of six different maps, with three more added over the game's lifespan. Players could fight on either the side of the United States Colonial Marines or on the side of the Aliens. Gameplay Īliens Online included asymmetric teams, teams consisting of more players than found in most first-person shooters of its era, job/class specialization, and RPG elements. It was based on the science fiction horror film Aliens. Aliens Online was a 1998 massively multiplayer first-person shooter video game released for Microsoft Windows.