99		S.T.A.L.K.E.R.: Shadow of Chernobyl (Windows, 2007)
99		S.T.A.L.K.E.R.: Call of Pripyat (Windows, 2009)
90		S.T.A.L.K.E.R.: Lost Alpha (Windows, 2014)
67		Half-Life 2: Episode Two (Windows, 2007)
66		Infestation: Survivor Stories (Windows, 2012)
66		Metro 2033 (Windows, 2010)
65		Crysis 2 (Windows, 2011)
65		Half-Life 2 (Windows, 2004)
65		Half-Life 2: Episode One (Windows, 2006)
64		Metro 2033: Redux (Windows, 2014)
64		You Are Empty (Windows, 2007)
62		Metro: Last Light (Windows, 2013)
62		Terminator 3: War of the Machines (Windows, 2003)
62		Homefront (Windows, 2011)
62		Codename: Tenka (Windows, 1998)
62		Half-Life 2: Deathmatch (Windows, 2004)
61		Ravaged (Windows, 2012)
61		Crysis 3 (Windows, 2013)
61		Far Cry 3: Blood Dragon (Windows, 2013)
61		The Terminator: Future Shock (DOS, 1995)
61		I Am Alive (Windows, 2012)
61		ZomDay (Windows, 2017)
61		Project Eden (Windows, 2001)
60		The Terminator 2029 (DOS, 1992)
60		Strife (DOS, 1996)
60		Dead Purge: Outbreak (Windows, 2017)
60		The Terminator: Rampage (DOS, 1993)
60		Burden (Windows, 2018)
60		Machine Head (DOS, 1996)
60		Band of Defenders (Windows, 2018)
60		SnipZ (Windows, 2017)
60		Arktika.1 (Windows, 2017)
60		Archangel (Windows, 2017)
60		DayZ (Windows, 2013)
60		Skynet Rising (Windows, 2016)
55		The Long Dark (Windows, 2014)
52		Arizona Sunshine (Windows, 2016)
52		Destiny 2 (Windows, 2017)
51		Unturned (Windows, 2017)
51		FireStarter (Windows, 2004)
50		Codename: Outbreak (Windows, 2001)
50		Overkill's The Walking Dead (Windows, 2018)
50		Diary of Defender (Windows, 2018)
50		7 Days to Die (Windows, 2013)
50		The Fifth Day (Windows, 2014)
50		Codename Cure (Windows, 2017)
50		Survarium (Windows, 2015)
50		Way of Hero (Windows, 2017)
50		Lonely Land (Windows, 2016)
50		Firefall (Windows, 2014)
50		Surface Tension (Windows, 1996)
50		Surface Tension (DOS, 1996)
50		Dead Inside (Windows, 2017)
50		The Flock (Windows, 2015)
40		Soviet Lunapark VR (Windows, 2018)

Notes: Games similar to S.T.A.L.K.E.R.: Clear Sky - Prologue, Games like S.T.A.L.K.E.R.: Clear Sky - Prologue, GSC Game World, Deep Silver, Inc., Windows, Action, Post-Apocalyptic, RPG elements, Shooter, 1st-person, PC, Game Similarities.