Alien enemies are a common theme in games, often portrayed as having bad intentions towards humankind. Halo: Combat Evolved features Master Chief defending humanity against invading Covenant aliens.

Set in the Alien universe, Alien: Rogue Incursion – Part One sees players suit up as rogue Colonial Marine Zula Hendricks on a mission to the planet Purdan (LV-354) in search of a former squadmate.