66		Return to Doom (DOS, 1988)
64		Solus (DOS, 1988)
62		Fallen Hero: Rebirth (Windows, 2018)
61		MetaHuman Inc. (Windows, 2015)
60		Rent-a-Vice (Windows, 2018)
60		Silverworld (Windows, 2018)
60		Reckless Space Pirates (Windows, 2017)
60		The Hero Project: Open Season (Windows, 2018)
60		Intergalactic Life (DOS, 2002)
60		The Away Team (Windows, 2016)
60		Diabolical (Windows, 2015)
60		Wraith Blaster (DOS, 1993)
60		Choice of the Petal Throne (Windows, 2015)
60		T-Rex Time Machine (Windows, 2017)
60		Versus: The Lost Ones (Windows, 2015)
54		The Hitchhiker's Guide to the Galaxy (DOS, 1984)
52		Fahrenheit 451 (DOS, 1984)
51		Suspended (DOS, 1983)
50		Tamoret: The Adventure to the Fourth Dimension (DOS, 1995)
50		The Martian Job (Windows, 2018)
50		Lifeline (Windows, 2017)
50		The ORPHEUS Ruse (Windows, 2015)
50		A Wise Use of Time (Windows, 2015)
50		Psy High (Windows, 2014)
50		Code 7 (Windows, 2017)
50		Hadean Lands (Windows, 2016)
50		Creatures Such as We (Windows, 2017)
50		Welcome to Moreytown (Windows, 2017)
50		Infinite Universe (Windows, 2014)
44		Starship Columbus (DOS, 1986)

Notes: Games similar to Countdown to Doom, Games like Countdown to Doom, Topologika Software Ltd., DOS, Adventure, Sci-Fi, Futuristic, Interactive Fiction, Text Adventure, Text-based, Spreadsheet, PC, Game Similarities.