The Only Wise
Windows
The Onyx Crown
The Oort Cloud 2020
The Ooze
Sega Mega Drive
Sega Technical Institute, Sonic Team
The Open League
The Operational Art of War I: 1939–1955
The Operational Art of War III
The Operational Art of War II: Modern Battles 1956–2000
The Operational Art of War IV
The Operative: No One Lives Forever
macOS, Windows, PlayStation 2
Monolith Productions
The Operator
Linux, macOS, Windows
The Oracle Land
The Orange
The Orange of Tomorrow
macOS, Linux, Windows
The OrangeRice
macOS, Windows
The Orb of Darkness
The Orca's III - Sektra Run
The Orca's IV - Consequences
The Orca's IV - Vfidê Chapter
The Orca's IV - War Regence
The Orchard of Stray Sheep
The Orc Invasion
The Ord Accord
The Order: 1886
PlayStation 4
Ready at Dawn
The Order of the Snake Scale
Linux, Windows
The Order of the Thorne - The King's Challenge
Infamous Quests
The ordinary case of Margaret Luoni
The Oregon Trail
Apple II series, Atari 8-bit family, Commodore 64, and 2 more
Minnesota Educational Computing Consortium
Nintendo Switch, Windows, iOS, and 1 more
Gameloft
Apple II
