The game is viewed from a first-person perspective. Players explore interconnected corridors and rooms, locate access cards and other objectives, and eliminate aliens using firearms and explosives.

Levels emphasize navigation through mazelike facilities. Progress depends on finding doors, switches, keys, ammunition, and health supplies while conserving resources and surviving increasingly dangerous encounters.

Map the facility mentally or with the in-game map, and search side rooms for access items before backtracking. Conserve ammunition for tougher aliens, keep moving in open corridors, and avoid entering unfamiliar rooms with low health. Check corners and doorways carefully because enemies can be difficult to see in the dark interiors.