Jogos
- O Gato e o Rato (Philips Odyssey)
- O Malabarista! / Jogo da Velha! (Philips Odyssey)
- O Segredo do Faraó! (Philips Odyssey)
- Obelix (Atari 2600)
- Obocchamakun (Nintendo Entertainment System - NES)
- Oceanhorn: Monster of Uncharted Seas (Macintosh)
- Oceanhorn: Monster of Uncharted Seas (PC)
- Oceanhorn: Monster of Uncharted Seas (Sony PlayStation 4)
- Oceanhorn: Monster of Uncharted Seas (Sony PlayStation Vita)
- Oceanhorn: Monster of Uncharted Seas (Nintendo Switch)
- Oceanhorn: Monster of Uncharted Seas (Microsoft Xbox One)
- Oceans Below (3DO)
- Octodad: Dadliest Catch (Sony PlayStation 4)
- Octodad: Dadliest Catch (Sony PlayStation Vita)
- Octopath Traveler (Nintendo Switch)
- Octopath Traveler (PC)
- Octopath Traveler (Google Stadia)
- Octopath Traveler (Microsoft Xbox One)
- Odama (Nintendo GameCube)
- Oddworld: Abe's Oddysee (Sony PlayStation)
- Oddworld: Abe's Oddysee - New 'n' Tasty (Microsoft Xbox One)
- Oddworld: Abe's Oddysee - New 'n' Tasty (Sony PlayStation 3)
- Oddworld: Abe's Oddysee - New 'n' Tasty (Sony PlayStation 4)
- Odin Sphere (Sony PlayStation 2)
- Odin Sphere Leifthrasir (Sony PlayStation Vita)
- Oeka Kids: Anpanman no Hiragana Daisuki (Nintendo Entertainment System - NES)
- Oeka Kids: Anpanman to Oekaki Shiyou!! (Nintendo Entertainment System - NES)
- Off the Wall (Atari 2600)
- Off Your Rocker (Atari 2600)
- Off-World Interceptor (3DO)
- Off-World Interceptor Extreme (Sony PlayStation)
- Off-World Interceptor Extreme (Sega Saturn)
- Offroad Thunder (Arcade)
- Ogre Battle 64: Person of Lordly Caliber (Nintendo 64)
- Ogre Battle: The March of the Black Queen (Super Nintendo)
- Ogura Hyakunin Isshu (3DO)
- Oink! (Atari 2600)
- Oishinbo: Kyukyoku no Menu 3bon Syoubu (Nintendo Entertainment System - NES)
- Ojousama Sousamou (NEC PC-FX)
- Okami (Sony PlayStation 2)
- Okamoto Ayako no Match Play Golf (Sega SG-1000)
- Okie Dokie (Atari 2600)
- Okkotoshi Puzzle Tonjan!? (Nintendo Entertainment System - NES)
- Oktoberfest: The Official Game (Nintendo DS)
- Old Towers (Sega Mega Drive)
- Olympic Gold (Sega Master System)
- Olympic Gold (Sega Game Gear)
- Olympic Gold (Sega Mega Drive)
- Olympic IQ (Nintendo Entertainment System - NES)
- Olympic Soccer: Atlanta 1996 (3DO)
- Olympic Soccer: Atlanta 1996 (Sega Saturn)
- Olympic Summer Games: Atlanta 1996 (3DO)
- Olympic Summer Games: Atlanta 1996 (Sega Mega Drive)
- Olympic Summer Games: Atlanta 1996 (Super Nintendo)
- Omega Race (Atari 2600)
- Omicron (Atari 2600)
- Omikron: The Nomad Soul (Sega Dreamcast)
- One (Nokia N-Gage)
- One (Sony PlayStation)
- One Man Game (Epoch TV Game System 10)
- One More Dungeon (Sony PlayStation 4)
- One More Dungeon (Sony PlayStation Vita)
- One More Dungeon (Nintendo Switch)
- One More Dungeon (Microsoft Xbox One)
- One Piece Grand Battle: Swan Colosseum (Bandai WonderSwan Color)
- One Piece: Chopper no Daibouken (Bandai WonderSwan Color)
- One Piece: Niji no Shima Densetsu (Bandai WonderSwan Color)
- One Piece: Pirate Warriors 3 (Sony PlayStation 4)
- One Piece: Pirate Warriors 3 (Sony PlayStation 3)
- One Piece: Pirate Warriors 3 (Sony PlayStation Vita)
- One Piece: Pirate Warriors 3 - Deluxe Edition (Nintendo Switch)
- One Piece: Treasure Wars (Bandai WonderSwan Color)
- One Piece: Treasure Wars 2: Buggyland e Youkoso (Bandai WonderSwan Color)
- One Piece: Unlimited World Red (Nintendo 3DS / 2DS)
- One Piece: Unlimited World Red (Sony PlayStation 3)
- One Piece: Unlimited World Red (Sony PlayStation Vita)
- One Piece: Unlimited World Red (Nintendo Wii U)
- One-on-One Basketball (Atari XEGS)
- One-on-One Basketball (Atari 7800)
- Oneesan to Issho! Janken Paradise (3DO)
- Oneesan to Issho! Kisekae Paradise (3DO)
- Oni Zero: Sengoku Ransei Hyakkaryouran (Nintendo DS)
- Onimusha 2: Samurai's Destiny (Sony PlayStation 2)
- Onimusha Blade Warriors (Sony PlayStation 2)
- Onimusha Essentials (Sony PlayStation 2)
- Onimusha: Dawn of Dream (Sony PlayStation 2)
- Onimusha: Demon Warrior (cancelado) (Sony PlayStation)
- Onimusha: Warlords (Sony PlayStation 2)
- Onimusha: Warlords (Sony PlayStation 4)
- Onimusha: Warlords (Nintendo Switch)
- Onimusha: Warlords (Microsoft Xbox One)
- Onita Atsushi: FMW (Super Nintendo)
- Online Start-Up Disc 4.0 (Sony PlayStation 2)
- Online Start-Up Disc V. 3.0 (Sony PlayStation 2)
- OnSide Soccer (3DO)
- Onyanko Town (Nintendo Entertainment System - NES)
- Open Sesame (Atari 2600)
- Operation Abyss: New Tokyo Legacy (Sony PlayStation Vita)
- Operation Abyss: New Tokyo Legacy (Limited Edition) (Sony PlayStation Vita)
- Operation C (Nintendo Game Boy)
- Operation Europe: Path to Victory 1939-45 (Super Nintendo)
- Operation Logic Bomb: The Ultimate Search & Destroy (Super Nintendo)
- Operation Shadow (Nokia N-Gage)
- Operation Thunderbolt (Super Nintendo)
- Operation Wolf (Sega Master System)NOVO
- Operation Wolf (Nintendo Entertainment System - NES)NOVO
- Operation Wolf (NEC Turbografx-16)NOVO
- Operation Wolf (MSX)NOVO
- Operation: Secret Storm (Nintendo Entertainment System - NES)
- Opus Castle (PC)
- Opus Castle (Nintendo Switch)
- OPUS Collection (Nintendo Switch)
- Orb 3-D (Nintendo Entertainment System - NES)
- Orebody: Binder's Tale (Nintendo Entertainment System - NES)
- Orguss (Sega SG-1000)
- Ori and the Blind Forest (Microsoft Xbox One)
- Ori and the Blind Forest - Definitive Edition (Microsoft Xbox One)
- Oriental Games (Commodore Amiga)
- Os Panzers Atacam! / Batalha Aeronaval! (Philips Odyssey)
- Oscar (Commodore Amiga CD32)
- Oscar's Trash Race (Atari 2600)
- Oshare Majo Love and Berry: DS Collection (Nintendo DS)
- Osomatsu-kun Hachamecha Gekijou (Sega Mega Drive)
- Osomatsu-Kun: Back to the Me no Deppa no Maki (Nintendo Entertainment System - NES)
- Otaku no Seiza: An Adventure in the Otaku Galaxy (Nintendo Entertainment System - NES)
- Othello (Nintendo Famicom Disk System (acessório))
- Othello (Bandai Super Vision 8000)
- Othello (Atari 2600)
- Othello (Sega SG-1000)
- Othello Killer (Commodore Amiga)
- Oukoku no Grand Chef (3DO)
- Out Of Control (Atari 2600)
- Out of Space (PC)
- Out of Space: Couch Edition (Nintendo Switch)
- Out of Space: Couch Edition (Microsoft Xbox One)
- Out of Space: Couch Edition (Sony PlayStation 4)
- Out of This World (3DO)
- Out of This World (Sega Mega Drive)
- Out of This World (Super Nintendo)
- Out to Lunch (Super Nintendo)
- Out Zone (Arcade)
- Outlanders (Nintendo Entertainment System - NES)
- Outlast (Microsoft Xbox One)
- Outlast (PC)
- Outlast (Sony PlayStation 4)
- Outlast 2 (Sony PlayStation 4)
- Outlast 2 (PC)
- Outlast 2 (Nintendo Switch)
- Outlast 2 (Microsoft Xbox One)
- Outlast Trinity (Sony PlayStation 4)
- Outlast Trinity (PC)
- Outlast Trinity (Microsoft Xbox One)
- Outlaw (Atari 2600)
- Outlaw (proto) (Atari Cosmos (protótipo))
- Outriders (Microsoft Xbox One)
- Outriders (Microsoft Xbox Series X|S)
- OutRun (Sega Mega Drive)
- OutRun (Arcade)
- OutRun (Sega Master System)
- OutRun (MSX1) (MSX)
- OutRun 3-D (Sega Master System)
- OutRun Europa (Sega Master System)
- OutRun2 (Microsoft Xbox)
- OutRunners (Sega Mega Drive)
- Outtrigger (Sega Dreamcast)
- Outworlder (Hanimex HMG-7900)
- Over Horizon (Nintendo Entertainment System - NES)
- Overdriven (Microsoft Xbox 360)
- Overdriven Reloaded (PC)
- Overdriven Reloaded: Special Edition (Nintendo Switch)
- Overdriven Reloaded: Special Edition (Macintosh)
- Overdriven Reloaded: Special Edition (Microsoft Xbox One)
- Overlord (Nintendo Entertainment System - NES)
- Overlord (Microsoft Xbox 360)
- Overlord II (Sony PlayStation 3)
- Overtake (Sharp X68000)
- OverTop (SNK Neo Geo Advanced Entertainment System)
- Overwatch (Microsoft Xbox One)
- OVNI! (Philips Odyssey)
- Oxenfree (Microsoft Xbox One)
- Oxenfree (Sony PlayStation 4)
- Oxenfree (Nintendo Switch)
- Oxenfree - Collector's Edition (Microsoft Xbox One)
- Oyaji Hunter Mahjong (3DO)
- Oystron (Atari 2600)
- Ozma Wars (Arcade)