45		Starcross (DOS, 1982)
44		Planetfall (DOS, 1983)
43		Amazon (DOS, 1984)
42		Timequest (DOS, 1991)
42		The Adventures of Buckaroo Banzai: Across the Eighth Dimension (DOS, 1985)
42		Rendezvous with Rama (DOS, 1985)
42		Frederik Pohl's Gateway (DOS, 1992)
42		Nine Princes in Amber (DOS, 1985)
42		Dopplegänger (DOS, 1985)
42		Star Trek: The Kobayashi Alternative (DOS, 1985)
41		Gateway II: Homeworld (DOS, 1993)
41		Die Höhlenwelt Saga: Der Leuchtende Kristall (DOS, 1994)
41		Star Trek: The Promethean Prophecy (DOS, 1986)
40		Projekt Prometheus (DOS, 1991)
40		Demoniak (DOS, 1991)
40		Versus: The Elite Trials (Windows, 2016)
40		Deliver Us the Moon: Fortuna (Windows, 2018)
40		Kingdom Without End (DOS, 2001)
40		Las llaves del tiempo (DOS, 1999)
40		The Star Portal (DOS, 1988)
40		Supernova (DOS, 1987)
40		Gun Mute (Windows, 2008)
40		Doctor Who: The Adventure Games (Windows, 2014)
40		Stationfall (DOS, 1987)
40		Frederik Pohl's Gateway (Windows, 1995)
40		Star Trek: First Contact (DOS, 1988)
40		The Twilight Zone (DOS, 1988)
40		Guardians of Infinity: To Save Kennedy (DOS, 1988)
40		Intergalactic Bar Mans Pub Crawl (DOS, 1991)

Notes: Games similar to Alien, Games like Alien, DOS, Adventure, Sci-Fi, Futuristic, Interactive Fiction, Text Adventure, Puzzle elements, PC, Game Similarities.