Outdoors Unlimited is the first game to combine hunting, fishing, and camping with a role-playing game system.
Oddworld: Abe's Oddysee - New 'n' Tasty
Oddworld: Abe's Oddysee - New 'n' Tasty is a classic platformer where you must rescue your fellow meat factory slaves.
Orc Attack: Flatulent Rebellion
Orc Attack is a hack-and-slash action game where fun-loving Orcs battle pollution loving Humans in a humorous fantasy setting.
Organic Panic is a quirky physics puzzler featuring real fluids, totally destructible levels, real fire, and an in-game editor to build and share your own levels.
Omerta: City of Gangsters
Omerta - City of Gangsters is a simulation game with tactical turn-based combat where players take the role of a fresh-from-the-boat immigrant with dreams of the big life who must work his way up the criminal hierachy of 1920's Atlantic City.
Of Orcs and Men
Of Orcs and Men is a role-playing game that places players in the role of an elite Orc soldier.
Oozi: Earth Adventure Episode 4
Oozi: Earth Adventure Episode 4 must use his kills to get past all the dangerous obstacles he will encounter on an alien planet.