Region | Title | System | Version | Edition | Languages | Serial | Status |
| O.D.T. | PC | | Original | | | |
| O.D.T. | PC | | Original | | | |
| O.R.B: Off-World Resource Base | PC | | Covermount | | | |
| O.R.B.: Orbital'nye Resursnye Bazy О.Р.Б.: Орбитальные Ресурсные Базы | PC | 1.03 | 1C: Kollekciya igrushek | | | |
| O'boy-jakten | PC | | Original | | | |
| Ob"ekt 69: Mest' Krassera Объект 69: Месть Крассера | PC | | Original | | | |
| Obduction | MAC | | Kickstarter | | | |
| Obduction | PC | 1.4.2 | Kickstarter | | | |
| Obitaemyj ostrov Обитаемый остров | PC | | Original | | | |
| Obitaemyj ostrov: Chuzhoj sredi chuzhix Обитаемый остров: Чужой среди чужих | PC | | Original | | | |
| Obitaemyj ostrov: Zemlyanin Обитаемый остров: Землянин | PC | | Original | | | |
| Obitel' T'my Обитель Тьмы | PC | 5.02 04/07/03 | Original | | | |
| Obitel' t'my: Sumerki Обитель тьмы: Сумерки | PC | 1.1 | Original | | | |
| Oblivious Garden: Carmina Burana (Disc 1) (Game Disk) | PC | 1.0 | Standard Edition | | | |
| Obratnyj otschet Обратный отсчет | PC | v.1 1.06.10.22 | Original | | | |
| Obrońca | PC | | FajnaGra.pl | | | |
| ObsCure (Disc 1) 惊悚空间 | PC | 1.0 | Original | | | |
| ObsCure (Disc 2) 惊悚空间 | PC | 1.0 | Original | | | |
| ObsCure (Disc 3) 惊悚空间 | PC | 1.0 | Original | | | |
| ObsCure (Disc 4) 惊悚空间 | PC | 1.0 | Original | | | |
| ObsCure | PC | | Original | | | |
| ObsCure | PC | | Software Pyramide | | | |
| ObsCure | PC | | Best of Atari | | | |
| ObsCure | PC | 1.1 | Covermount | | | |
| ObsCure (Disc 1) | PC | | Original | | | |
| ObsCure (Disc 2) | PC | | Original | | | |
| ObsCure (Disc 3) | PC | | Original | | | |
| ObsCure (Disc 4) | PC | | Original | | | |
| ObsCure II | PC | | Original | | | |
| ObsCure II | PC | 1.0 | Covermount | | | |
| ObsCure II | PC | 1.0.0.0 | Original | | | |
| Obsidian (Disc 1) | PC | | Original | | | |
| Obsidian (Disc 2) | PC | | Original | | | |
| Obsidian (Disc 3) | PC | | Original | | | |
| Obsidian (Disc 4) | PC | | Original | | | |
| Obsidian (Disc 5) | PC | | Original | | | |
| Obsidian: Alla Frontiera della Logica (Disc 1) | PC | 1.0.001 | Original | | | |
| Obsidian: Alla Frontiera della Logica (Disc 2) | PC | 1.0.001 | Original | | | |
| Obsidian: Alla Frontiera della Logica (Disc 3) | PC | 1.0.001 | Original | | | |
| Obsidian: Alla Frontiera della Logica (Disc 4) | PC | 1.0.001 | Original | | | |
| Obsidian: Alla Frontiera della Logica (Disc 5) | PC | 1.0.001 | Original | | | |
| Ocean Jewels | PC | | Red Rocks | | | |
| Ochazukenori: Kaiki!! Mushi Danshaku no Yakata 御茶漬海苔 怪奇!!蟲男爵の館 | PC | | Original | | | |
| Oddworld: Abe's Exoddus (Install Disc) | PC | 2.0 | Original | | | |
| Oddworld: Abe's Exoddus (Play Disc) | PC | 2.0 | Original | | | |
| Oddworld: Abe's Exoddus (CD Installieren) | PC | 2.0 | Original | | | |
| Oddworld: Abe's Exoddus (CD Abspielen) | PC | 2.0 | Original | | | |
| Oddworld: Abe's Exoddus (Disc 1) | PC | 1.0 | Covermount | | | |
| Oddworld: Abe's Exoddus (Disc 2) | PC | 1.0 | Covermount | | | |
| Oddworld: Abe's Origins | PC | | Limited Run Games | | | |
| Odens Öga Odens Öga! | PC | 1.0.0 | Original | | | |
| Odium ōdi·um | PC | | Covermount | | | |
| Odlikas za Prvake Одликаш за Прваке | PC | | Original | | | |
| Odnazhdy' v Chikago Однажды в Чикаго | PC | 1.1.0.0 | Original | | | |
| Odyssey (Disc 1) 奧德賽 | PC | | Original | | | |
| Odyssey (Disc 2) 奧德賽 | PC | | Original | | | |
| Odyssey: The Legend of Nemesis | MAC | 1.0 | Original | | | |
| Odyssey: The Search for Ulysses (Disc 1) | PC | | Original | | | |
| Odyssey: The Search for Ulysses (Disc 2) | PC | | Original | | | |
| Of Light and Darkness: The Prophecy (Disc 1) | PC | | Original | | | |
| Of Light and Darkness: The Prophecy (Disc 2) | PC | | Original | | | |
| Of Light and Darkness: The Prophecy (Disc 3) | PC | | Original | | | |
| Off-World Interceptor | 3DO | | Original | | | |
| Offensive | PC | | Original | | | |
| Offensive Offensive War: The Ultimate Strategical Combat Game | PC | | Covermount | | | |
| The Office | PC | | Original | | | |
| Official Formula 1 Racing | PC | | Original | | | |
| Offroad Extreme! Special Edition | PC | | Original | | | |
| Oficery: Special'noe izdanie Офицеры: Специальное издание | PC | 1.18.2 | Original | | | |
| Ognisty Podmuch: Fire Captain (Disc 1) (Dysk Instalacyjny) | PC | | Covermount | | | |
| Ognisty Podmuch: Fire Captain (Disc 2) (Dysk z Grą) | PC | | Covermount | | | |
| Oh-chan no Oekaki Logic for Palm おーちゃんのお絵かきロジック for Palm | PALM | 1.04 | Original | | | |
| Oil Platform Simulator | PC | 1.0 | Original | | | |
| Oil Rush | PC | | Original | | | |
| Oil Tycoon | PC | 1.0 | Original | | | |
| Oil Tycoon | PC | 1.01 | Original | | | |
| Oil Tycoon 2 | PC | | Original | | | |
| Oil Tycoon 2 | PC | | Covermount | | | |
| OIO: The Game: Enlarged | PC | | F*ckn' Best of Independent Games: Collection Vol. 1 | | | |
| Okano Software Classics: Volume 2 | PC | | Original | | | |
| Okigaru Igo Taikyoku お気軽囲碁対局 | PALM | | Original | | | |
| Okigaru Igo Taikyoku お気軽囲碁対局 | PPC | | Original | | | |
| Oktoberfest Wiesn-Gaudi | PC | 1.0 | Original | | | |
| Oldtimer | ACD | | Original | | | |
| Oldtimer: Erlebte Geschichte Teil II | PC | | Original | | | |
| Olimpiada Zimowa 2002 Olimpijskie Zmagania 2002 | PC | | Original | | | |
| Olympiad Qiaosai 2 奧林匹亞橋賽2 | PC | | Original | | | |
| Olympic Games: Atlanta 1996 | PC | | Original | | | |
| Olympic Soccer | PC | | Kixx | | | |
| Olympic Soccer | PC | | CD-ROM Classic Collection 2 | | | |
| Omar Sharif Bridge | PC | 1.0 | Original | | | |
| The Omega Stone: Riddle of the Sphinx II (Disc 1) | PC | 1.2.3.2 | Original | | | |
| The Omega Stone: Riddle of the Sphinx II (Disc 2) | PC | 1.2.3.2 | Original | | | |
| The Omega Stone: Riddle of the Sphinx II (Disc 3) | PC | 1.2.3.2 | Original | | | |
| The Omega Stone: Riddle of the Sphinx II (Disc 4) | PC | 1.2.3.2 | Original | | | |
| Omikron: The Nomad Soul (Disc 1) | PC | 1.0 | Original | | | |
| Omikron: The Nomad Soul (Disc 2) | PC | 1.0 | Original | | | |
| Omikron: The Nomad Soul (Disc 3) | PC | 1.0 | Original | | | |
| Ominous Horizons Ominous Horizons: A Paladin's Calling | PC | 1.0 | Original | | | |
| OMSI: Der Omnibussimulator | PC | 1.04 | OMSI Bundle | | | |
| On the Ball: League Edition | PC | 1.0 | Original | | | |
| On the Ball: World Cup Edition | PC | 1.00 | Original | | | |
| On-Robot Он-Робот | PC | 1.14SB | 1C: Igrushki | | | |
| One Must Fall 2097 | PC | | Original | | | |
| One Must Fall: Battlegrounds | PC | 2090 | Original | | | |
| One Must Fall: Battlegrounds | PC | 2090 | Original | | | |
| One Step Beyond | PC | | Hit Squad: Regenerator | | | |
| OnEscapee | ACD | | Original | | | |
| Oni 奥妮 | PC | 1.7 | Original | | | |
| Oni | PC | 1.0 | Original | | | |
| Oni | PC | 1.0 | Covermount | | | |
| Oni | PC | 1.0 | Covermount | | | |
| Oni Они | PC | 1.0 | | | | |
| Oni | MAC | | Original | | | |
| Oni | PC | 1.0 | Original | | | |
| Oni no Kamen 鬼ノ仮面 | PC | 1.00 | Original | | | |
| Onible'jd Ониблэйд | PC | | Original | | | |
| Onigunsou Kuramochi Yuzo no Yatchimasu: Spartan Manshu 鬼軍曹倉持勇造の殺っちます ~スパルタン満州~ | PC | | Original | | | |
| Onii-chan Jushin-chuu お兄ちゃん受信中 | PC | | Original | | | |
| Onimusha: Put' samuraja Onimusha: Путь самурая | PC | | Original | | | |
| Onimusha: Put' samuraya (Disc 1) (Igrovoj) Onimusha: Путь самурая | PC | | Original | | | |
| Onimusha: Put' samuraya (Disc 2) Onimusha: Путь самурая | PC | | Original | | | |
| Onimusha: Put' samuraya (Disc 3) Onimusha: Путь самурая | PC | | Original | | | |
| Onimusha: Put' samuraya (Disc 4) Onimusha: Путь самурая | PC | | Original | | | |
| Onkel Alberts geheimnisvolles Notizbuch | PC | | Original | | | |
| OnlineGamez | PC | | | | | |
| Only You: Seikimatsu no Juliet-tachi Only You ~世紀末のジュリエットたち~ | FMT | | Shokai Gentei | | | |
| Onsen de Takkyuu 温泉de卓球 | PC | | Original | | | |
| OnSide Soccer | 3DO | | Unlicensed (oldergames, Good Deal Games Double Header! Two Game Set) | | | |
| Oozora ni Kodawarou! Minna no Kuukou 2 大空にこだわろう! みんなの空港2 | PC | | | | | |
| Open Kart | PC | | I Videogiochi del "Giornalino" | | | |
| Open Season (Disc 1) | PC | 1.00 | Original | | | |
| Opera Fatal | PC | | Original | | | |
| Operaciya "Plastilin" (Disc 1) Операция "Пластилин" | PC | | Original | | | |
| Operaciya "Plastilin" (Disc 2) Операция "Пластилин" | PC | | Original | | | |
| Operaciya Bagration Операция Багратион | PC | | Original | | | |
| Operaciya Silent Storm (Disc 1) Операция Silent Storm | PC | Aug 11 2003 | 1C: Igroteka | | | |
| Operaciya Silent Storm (Disc 2) Операция Silent Storm | PC | Aug 11 2003 | 1C: Igroteka | | | |
| Operaciya Silent Storm: Chasovye (Disc 1) Операция Silent Storm: Часовые | PC | | 1С: Igroteka | | | |
| Operaciya Silent Storm: Chasovye (Disc 2) Операция Silent Storm: Часовые | PC | | 1С: Igroteka | | | |
| Operation | PC | | General Mills | | | |
| Operation Barbarossa: The Struggle for Russia | PC | | Original | | | |
| Operation Body Count | PC | | Original | | | |
| Operation Europe: Path to Victory 1939-45 | PC | | Original | | | |
| Operation Flashpoint: Cold War Crisis | PC | 1.46 | Sold Out Software | | | |
| Operation Flashpoint: Cold War Crisis | PC | 1.46 | Sold Out Software | | | |
| Operation Flashpoint: Cold War Crisis | PC | | The Games Collection | | | |
| Operation Flashpoint: Holodnaja vojna Операция Flashpoint: Холодная война | PC | 1.46 | Original | | | |
| Operation Mittelmeer | PC | | Original | | | |
| Operation Thunderstorm | PC | 1.0 | Original | | | |
| Operation: Surgery Has Never Been so Silly! | PC | | Sold Out Software | | | |
| The Operational Art of War II: 1956-2000 The Operational Art of War II: Bewaffnete Konflikten | PC | | Original | | | |
| The Operational Art of War: Century of Warfare | PC | | Original | | | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.0.0.4 | Game of the Year Edition (Covermount) | | | |
| The Operative: No One Lives Forever (Disc 1) ノーワンリブスフォーエバー | PC | 1.004, 1.004J | Original | | | |
| The Operative: No One Lives Forever (Disc 2) ノーワンリブスフォーエバー | PC | 1.004, 1.004J | Original | | | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.0 | Original | | | |
| The Operative: No One Lives Forever (Disc 1) (Game Disc) | MAC | 1.004 | MacPlay | | | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.004 | Game of the Year Edition | | | |
| The Operative: No One Lives Forever (Disc 2) | PC | 1.0 | Original | | | |
| Opowieści z Narnii: Książe Kaspian | PC | | Covermount | | | |
| Opowieści z Narnii: Lew, Czarownica i Stara Szafa (Disc 1) | PC | | Original | | | |
| Opowieści z Narnii: Lew, Czarownica i Stara Szafa (Disc 2) | PC | | Original | | | |
| Opowieści z Narnii: Lew, Czarownica i Stara Szafa (Disc 3) | PC | | Original | | | |
| Opowieści z Narnii: Lew, Czarownica i Stara Szafa (Disc 4) | PC | | Original | | | |
| Opsys | PC | | Original | | | |
| The Orange Box (Disc 1) | PC | | Rerelease | | | |
| The Orange Box (Disc 1) | PC | | Rerelease | | | |
| The Orange Box (Disc 1) | PC | | Original | | | |
| The Orange Box (Disc 2) | PC | | Rerelease | | | |
| The Orange Box (Disc 2) | PC | | Rerelease | | | |
| The Orange Box (Disc 2) | PC | | Original | | | |
| Orbatak | 3DO | | Arcade CD-ROM | | | |
| Orda: Severnyj veter Орда: Северный ветер | PC | | Original | | | |
| Order of War: Osvobozhdenie Order of War: Освобождение | PC | | Igromaniya: Vybor redakcii | | | |
| Order of War: Stolknovenie Order of War: Столкновение | PC | | Igromaniya: Vybor redakcii | | | |
| The Oregon Trail 3rd Edition: Pioneer Adventures (Disc 1) | PC | 1.2a | Bundle Version Compaq Presario OEM | | | |
| Oregon Trail II + Logic Quest | PC | 1.2/1.0 | Original | | | |
| The Oregon Trail | PC | 1.21 | | | | |
| Ori and the Blind Forest: Definitive Edition | PC | 5.3.2.9582331 | Limited Edition | | | |
| The Original Links | PC | | Solid Gold Edition | | | |
| Die Original Moorhuhn Jagd | PC | | Best of Moorhuhn | | | |
| The Original Mulan 花木兰 | PC | | Original | | | |
| Original War (Disc 1) | PC | | Original | | | |
| Original War (Disc 2) | PC | | Original | | | |
| Original War (Disc 1) | PC | 1.02 | Covermount | | | |
| Original War (Disc 2) | PC | 1.02 | Covermount | | | |
| Original War (Disc 1) (Install Disc) オリジナル ウォー | PC | 1.02 | Original | | | |
| Original War (Disc 2) (GameDisc) オリジナル ウォー | PC | 1.02 | Original | | | |
| Orion Burger | PC | | Original | | | |
| The Orion Conspiracy | PC | 1.01 | Original | | | |
| Orion's Puzzle Collection | DC | 1.000 | Unlicensed | | | |
| Orly Pervoj mirovoj Орлы Первой мировой | PC | 02.19.07 | Original | | | |
| Oro e Gloria: La Strada per El Dorado | PC | | Covermount | | | |
| Oro Negro: Juego de Guerra y Estrategia | PC | | Covermount | | | |
| Osada Avalona (Disc 1) Осада Авалона | PC | | | | | |
| Osada Avalona (Disc 2) Осада Авалона | PC | | | | | |
| Oscar | PC | | Golden Zone | | | |
| Oscar | PC | | Original | | | |
| Oscar | PC | | Jackson Libri | | | |
| Oscar der Ballonfahrer und die Geheimnisse des Waldes | PC | | | | | |
| Oscar the Balloonist: Discovers the Farm 小小探險家奧斯卡 農場奇遇記 | PC | | Original | | | |
| Osobennosti nacional'nogo razvoda (Disc 1) Особенности национального развода | PC | | Original | | | |
| Osobennosti nacional'nogo razvoda (Disc 2) Особенности национального развода | PC | | Original | | | |
| Ost-Indskaya kompaniya: Zolotoe izdanie Ост-Индская компания: Золотое издание | PC | | Original | | | |
| Osterspiele-Box Oster Spielebox | PC | | Original | | | |
| Ostrich Runner | PC | | Microforum | | | |
| Ostrov e'rotiki Остров эротики | PC | | Original | | | |
| Ostrov Nanda Остров Нанда | PC | 1.000 | Original | | | |
| Ot zakata do rassveta От заката до рассвета | PC | | 1C: Igroteka | | | |
| Otchayannye domoxozyajki (Disc 1) (Ustanovochnyj disk) Отчаянные домохозяйки | PC | | Original | | | |
| Otchayannye domoxozyajki (Disc 2) (Ustanovochnyj disk) Отчаянные домохозяйки | PC | | Original | | | |
| Otchayannye domoxozyajki (Disc 3) (Igrovoj disk) Отчаянные домохозяйки | PC | | Original | | | |
| Othelanian Wars オセラニアン・ウォーズ | PC | | Original | | | |
| Othello | PC | | Original | | | |
| Othello CD-ROM | PC | | Original | | | |
| Otorva v shkole Оторва в школе | PC | | Original | | | |
| Otto's Ottifanten | PC | | Original | | | |
| Oudou Aniki 王道兄貴 | PC | 1.20b | Original | | | |
| Oujisama Lv1 王子さまLv1 | PC | | Original | | | |
| Our Worst Fears: Die Blumen des Todes | PC | | Original | | | |
| Out of This World | 3DO | | Original | | | |
| Out of This World | 3DO | RE | 3DO Maniac Pack | | | |
| Outbreaker | PC | | Original | | | |
| Outcast | PC | | Original | | | |
| Outcast (Disc 1) | PC | | Play the Games Vol. 3 | | | |
| Outcast (Disc 2) | PC | | Play the Games Vol. 3 | | | |
| Outcast (Disc 1) | PC | | Covermount | | | |
| Outcast (Disc 2) | PC | | Covermount | | | |
| The Outforce | PC | 1.0.0.0 | Original | | | |
| Outlaw Racers | PC | | Sold Out Software | | | |
| Outlaws (Disc 1) | PC | | Original | | | |
| Outlaws (Disc 1) | PC | 2.0 | Collection LucasArts | | | |
| Outlaws (Disc 2) | PC | | Original | | | |
| Outlaws (Disc 2) | PC | 2.0 | Collection LucasArts | | | |
| Outlaws (Disc 1) | PC | 1.0 | Original | | | |
| Outlaws (Disc 1) | PC | 1.1 | Rerelease | | | |
| Outlaws (Disc 2) | PC | 1.0 | Original | | | |
| Outlaws (Disc 2) | PC | 1.1 | Rerelease | | | |
| Outlaws: Die Gesetzlosen (Disc 1) | PC | 1.1.1 | Original | | | |
| Outlaws: Die Gesetzlosen (Disc 2) | PC | 1.1.1 | Original | | | |
| Outlive | PC | 1.01 | Original | | | |
| Outlive | PC | 1.01 | Original | | | |
| Outpost | PC | 1.5 | Rerelease, Sierra Originals | | | |
| Outpost 2: Destini Sospesi | PC | 1.0 | Covermount | | | |
| Outpost 2: Divided Destiny | PC | | SierraOriginals | | | |
| Outpost 2: Divided Destiny | PC | 1.2.0.5 | Original | | | |
| Outpost 2: Divided Destiny | PC | 1.2.0.5 | Original | | | |
| Outrage | PC | | Original | | | |
| OutRun 2006: Coast 2 Coast (Disc 1) | PC | | Original | | | |
| OutRun 2006: Coast 2 Coast (Disc 2) | PC | | Original | | | |
| Ovech'i bega Овечьи бега | PC | 1.0 | Original | | | |
| Over 1000 Games: The Complete Encyclopedia of Games (Disc 1) | PC | | Original | | | |
| Over 1000 Games: The Complete Encyclopedia of Games (Disc 2) | PC | | Original | | | |
| Over 350 Solitaire Games | PC | | Original | | | |
| Overboard! | PC | | Original | | | |
| Overclocked: Una Storia di Violenza | PC | 1.1 | Original | | | |
| Overlord BGamer 153 (Side A) | PC | | Covermount | | | |
| Overlord | PC | 1.2 | Original | | | |
| Overlord II | PC | | Original | | | |
| Overwatch | PC | | Origins Edition | | | |
| Owlboy (Game Disc) | PC | 0.0.6152.604 | IndieBox | | | |
| Oynayarak Ogreniyorum 1 Oynayarak Öğreniyorum 1 | PC | | Original | | | |
| Oyunlarla Dil Bilgisi Oyunlarla Matematik | PC | | Original | | | |
| Ozawa-Ken+ | PC | | Original | | | |
| Overkill & Lunar-C | CD32 | | Original | | /DP130002 | |
| The Oregon Trail | PC | 1.1 | Original | | #HCD606 | |
| The Oregon Trail | PC | 1.2 | Original | | #HCD706 | |
| The Oregon Trail | PC | 1.2 | Original | | #HCD706 | |
| Oregon Trail II | PC | 1.31 | Rerelease | | #HCD744AE-CD | |
| Oregon Trail II: 25th Anniversary Limited Edition | PC | 1.3 | Original, SoftKey | | #OTR744AE-CD | |
| Over 350 Jigsaw Puzzles | PC | | Original | | 012163 | |
| Olivers Äventyr: Drakens Förbannelse | PC | | Original | | 021120110 | |
| Outwars (Disc 2) | PC | 1.0 | Original | | 0298 Part No. X03-57509 | |
| Outwars (Disc 2) | PC | 1.0 | Original | | 0298 Part No. X03-57509 | |
| Outwars (Disc 1) | PC | 1.0 | Original | | 0298 Part No. X03-63527 | |
| Outwars (Disc 1) | PC | 1.0 | Original | | 0298 Part No. X03-63527 | |
| Outwars (Disc 1) | PC | 1.0 | Original | | 0398 Artikelnr. X00-14039 DE | |
| Outwars (Disc 2) | PC | 1.0 | Original | | 0398 Artikelnr. X00-14040 DE | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Original | | 04-12608CD | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Channelware | | 04-15303 | |
| Oddworld: Abe's Exoddus (Install) | PC | 2.0 | Original | | 04-15993CD1 | |
| Oddworld: Abe's Exoddus (Play) | PC | | Original | | 04-15993CD2 | |
| One Unit Whole Blood | PC | 1.21 | Original | | 04-16459CD1 | |
| Overwatch | PC | | Origins Edition | | 052429 | |
| Outlaws: Cidade Sem Lei (Disc 1) | PC | 2.0 | Original | | 0806.05.0 | |
| Outlaws: Cidade Sem Lei (Disc 2) | PC | 2.0 | Original | | 0806.06.0 | |
| Oregon Trail II | PC | 1.3 | Smart Saver | | 0TT744AE-CD | |
| Ona: Sbornik e'roticheskix igr Она: Сборник эротических игр | PC | | Original | | 10-20999 | |
| Outward | PC | | Day One Edition | | 1024669LAINT, 103699 | |
| Obsidian (Disc 1) | PC | | Original | | 11008 | |
| Obsidian (Disc 1) | PC | | Original, Complimentary Copy | | 11008 | |
| Obsidian (Disc 2) | PC | | Original, Complimentary Copy | | 11008 | |
| Obsidian (Disc 3) | PC | | Original, Complimentary Copy | | 11008 | |
| Obsidian (Disc 4) | PC | | Original, Complimentary Copy | | 11008 | |
| Obsidian (Disc 5) | PC | | Original | | 11008 | |
| Obsidian (Disc 5) | PC | | Original, Complimentary Copy | | 11008 | |
| Opera Fatal | PC | | Tandem | | 1444 | |
| OutRun 2006: Coast 2 Coast | PC | | GSP White Label: Reload | | 1673A | |
| OutRun 2006: Coast 2 Coast | PC | | White Label | | 1673A | |
| Oni | PC | 1.0 | PC Best Buy | | 177588 | |
| O.R.B: Off-World Resource Base | PC | 1.0 | Original | | 22434CD | |
| Outlaws (Disc 1) | PC | 2.0 | LucasArts Classics | | 3000009.101.UK | |
| Outlaws (Disc 2) | PC | 2.0 | LucasArts Classics | | 3000009.102.UK | |
| Odin Klik Один Клик | PC | | Original | | 301/2002 | |
| The Oregon Trail 5th Edition: Adventures Along the Oregon Trail | PC | 1.0 | Original | | 380859-CD | |
| The Oregon Trail 5th Edition: Adventures Along the Oregon Trail | PC | 1.0 | Scholastic | | 380859-CD WP2 | |
| The Oregon Trail 5th Edition: Adventures Along the Oregon Trail | PC | 1.0 | Original | | 380859A-CD | |
| The Oregon Trail 5th Edition: Adventures Along the Oregon Trail | PC | 1.1 | Rerelease, Southwestern School Set | | 380859B-CD | |
| Outlaws (Disco 1) | PC | 1.0 | LucasArts Classic | | 41175.101.IT | |
| Outlaws (Disco 2) | PC | 1.0 | LucasArts Classic | | 41175.102.IT | |
| Outcast (Disc 1) | PC | | Original | | 42831-9110TC | |
| Outcast (Disc 2) | PC | | Original | | 42831-9110TC | |
| Onimusha 3 | PC | | Original | | 5004561 | |
| Open Season (Disc 1) | PC | 1.00 | Original | | 5004904-CD 1 | |
| Open Season (Disc 2) | PC | 1.00 | Original | | 5004904-CD 2 | |
| Open Season (Disc 3) | PC | 1.00 | Original | | 5004904-CD 3 | |
| Open Season (Disc 1) | PC | | Original | | 5004905-CD 1 | |
| Open Season (Disc 2) | PC | | Original | | 5004905-CD 2 | |
| Open Season (Disc 3) | PC | | Original | | 5004905-CD 3 | |
| Outtrigger | DC | 1.003 | Original | | 51102 | |
| Ooga Booga | DC | 1.001 | Original | | 51140 | |
| Outlaws (Disc 1) | PC | 1.0 Build 3 | Bundle Version Diamond OEM | | 644430 | |
| Outlaws (Disc 2) | PC | 1.0 Build 3 | Bundle Version Diamond OEM | | 644431 | |
| Onimusha 3: Demon Siege (Disc 1) | PC | | Original | | 683100-CD1 | |
| Onimusha 3: Demon Siege (Disc 2) | PC | | Original | | 683100-CD2 | |
| Onimusha 3: Demon Siege (Disc 3) | PC | | Original | | 683100-CD3 | |
| Open Season (Disc 1) | PC | 1.0 | Original | | 683131-CD1 | |
| Open Season (Disc 2) | PC | 1.0 | Original | | 683131-CD2 | |
| Open Season (Disc 3) | PC | 1.0 | Original | | 683131-CD3 | |
| Operation Omega | PC | | Original | | 7-20286-92175-1 | |
| ObsCure | PC | 1.0 | Original | | 719 02 102 | |
| ObsCure | PC | | Original | | 71902134 | |
| Overwatch | PC | | Game of the Year Edition, Legendary Edition | | 73052010US, S7302210 | |
| Oxyd Magnum! Gold Edition | PC | | Game-Pack 3 | | 80227 | |
| Origami | CDI | | Original | | 810 0041 | |
| Othello | CDI | | Original | | 810 0163 | |
| L'Open de Palm Springs | CDI | | Original, For Demonstration Only | | 812 0002 | |
| Ouro e Glória: O Caminho para El Dorado | PC | | Original | | 906.02.0 | |
| Outlaws (Disc 1) | PC | 1.0 | Original | | 9511830 | |
| Outlaws (Disc 1) | PC | 1.0 Build 3 | Original | | 9511830 | |
| Outlaws (Disc 1) | PC | 2.0 | Rerelease | | 9511830 | |
| Outlaws (Disc 1) | PC | 2.0 | Rerelease | | 9511830 | |
| Outlaws (Disc 1) | PC | 2.0 | Rerelease | | 9511830 | |
| Outlaws (Disc 2) | PC | 1.0 | Original | | 9511831 | |
| Outlaws (Disc 2) | PC | 1.0 Build 3 | Original | | 9511831 | |
| Outlaws (Disc 2) | PC | 2.0 | Rerelease | | 9511831 | |
| Outlaws (Disc 2) | PC | 2.0 | Rerelease | | 9511831 | |
| Outlaws (Disc 2) | PC | 2.0 | Rerelease | | 9511831 | |
| The Orange Box (Disc 1) | PC | | Original, EA Classics | | 985207, VAE07705811D, VAE07705811D/ENG, VAE07707118D/ENG, VAX07705811D/AUS | |
| The Orange Box (Disc 2) | PC | | Original | | 985217 | |
| Othello | PC | | Original | | 99011 | |
| Oddworld: Abe's Exoddus (Installazione) | PC | 1.0 | Replay | | ABEXPCREI/A1 | |
| Oddworld: Abe's Exoddus (Gioco) | PC | 1.0 | Replay | | ABEXPCREI/A2 | |
| OverTop オーバートップ | NGCD | | Original | | ADCD-011 | |
| Oshidashi Zintrick ~ ZinTricK 押し出しジントリック | NGCD | | Original | | ADCD-104 | |
| Ougon Musou Kyoku X 黄金夢想曲X | XBOX360 | | Original | | AJ-2003 | |
| Ore no Shita de Agake 俺の下であがけ | PC | System3.9 Ver.5.43 | Original | | ALB-005 | |
| Oudou Yuusha 王道勇者 | PC | | Original | | ALS-0029 | |
| Operation | PC | | General Mills | | AM0703R71 | |
| Operation | PC | | General Mills | | AM801R5 | |
| Operation Darkness | XBOX360 | | Original | | AT-2002 | |
| One Piece: Kaizoku Musou ワンピース 海賊無双 | PS3 | 01.02 | Original, Treasure Box | | BLAS 50450 … | |
| One Piece: Kaizoku Musou 2 One Piece 海賊無雙 2 | PS3 | 01.00 | Original | | BLAS 50597 | |
| One Piece: Unlimited World R | PS3 | 01.01 | Original | | BLAS 50699 | |
| The Orange Box | PS3 | 01.00 | Original | | BLES-00153 | |
| The Orange Box | PS3 | 01.00 | Original | | BLES-00171 | |
| The Orange Box | PS3 | 01.00 | Original | | BLES-00172 | |
| Overlord: Raising Hell | PS3 | 01.00 | Original | | BLES-00257 | |
| Overlord II | PS3 | 01.02 | Original | | BLES-00580 | |
| Operation Flashpoint: Dragon Rising | PS3 | 01.01 | Original, Promo | | BLES-00597 | |
| Operation Flashpoint: Red River | PS3 | 01.01 | Original | | BLES-01171 | |
| Obut Pétanque | PS3 | 01.01 | Original | | BLES-01340 | |
| Order Up!! | PS3 | 01.04 | Original | | BLES-01470 | |
| Of Orcs and Men | PS3 | 01.01 | Original | | BLES-01586 | |
| One Piece: Pirate Warriors | PS3 | 01.01 | Original | | BLES-01672 … | |
| One Piece: Pirate Warriors | PS3 | 02.00 | Original, Essentials | | BLES-01672 … | |
| Obut Pétanque 2 | PS3 | 01.01 | Original | | BLES-01696 | |
| One Piece: Pirate Warriors 2 | PS3 | 01.00 | Original | | BLES-01913 | |
| One Piece: Unlimited World Red | PS3 | 01.00 | Original | | BLES-02020 | |
| One Piece: Pirate Warriors + One Piece: Pirate Warriors 2 | PS3 | 01.00 | Original | | BLES-02131 | |
| One Piece: Pirate Warriors 3 | PS3 | 01.00 | Original | | BLES-02140 | |
| Odin Sphere: Leifthrasir | PS3 | 01.00 | Original | | BLES-02241 | |
| Ookami: Zekkeiban 大神 絶景版 | PS3 | 00.00 | Original, PlayStation 3 the Best, PlayStation 3 the Best (Reprint) | | BLJM 55061 … | |
| Operation Flashpoint: Dragon Rising | PS3 | 01.01 | Original | | BLJM 60152 | |
| Operation Flashpoint: Red River | PS3 | 01.02 | Original, Codemasters the Best | | BLJM 60361 … | |
| One Piece: Kaizoku Musou 2 ワン・ピース ~海賊無双2~ | PS3 | 01.02 | Treasure Box | | BLJM 60572 | |
| Oretachi ni Tsubasa wa Nai 俺たちに翼はない | PS3 | 01.01 | Original | | BLJM 61018 | |
| Odin Sphere: Leifthrasir オーディンスフィア レイヴスラシル | PS3 | 01.00 | Original | | BLJM 61239 | |
| One Piece: Kaizoku Musou 3 ワンピース 海賊無双3 | PS3 | 01.01 | Original | | BLJM 61261 | |
| Oneechanbara Z: Kagura with NoNoNo! お姉チャンバラZ~カグラ~ With NoNoNo! | PS3 | 01.03 | Original | | BLJS 10221 | |
| Ore no Imouto ga Konnani Kawaii Wake ga Nai. Happy End 俺の妹がこんなに可愛いわけがない。 ハッピーエンド | PS3 | 01.01 | Original | | BLJS 10238 | |
| One Piece: Unlimited World R ワンピース アンリミテッドワールド R | PS3 | 01.01 | Original | | BLJS 10272 | |
| Operation Flashpoint: Dragon Rising 오퍼레이션 플래시포인트: 드래곤 라이징 | PS3 | 01.01 | Original | | BLKS 20157 | |
| The Orange Box | PS3 | 01.00 | Original | | BLUS-30055 | |
| Overlord: Raising Hell | PS3 | 01.00 | Original | | BLUS-30143 | |
| Operation Flashpoint: Dragon Rising | PS3 | 01.01 | Original | | BLUS-30316 | |
| Overlord II | PS3 | 01.01 | Original | | BLUS-30317 | |
| Operation Flashpoint: Red River | PS3 | 01.01 | Original | | BLUS-30704 | |
| Order Up!! | PS3 | 01.02 | Original | | BLUS-30904 | |
| One Piece: Unlimited World Red | PS3 | 01.00 | Day One Edition | | BLUS-31427 … | |
| Odin Sphere: Leifthrasir | PS3 | 01.01 | Original | | BLUS-31601 | |
| Oddworld: Stranger's Wrath HD | PS3 | 01.00 | Original | | BLUS-31620 | |
| Oddworld: Abe's Oddysee: New 'n' Tasty! | PS3 | 01.00 | Limited Edition | | BLUS-31621 | |
| On Air | PC | | Original | | BROWNIE 990201 | |
| Of Light and Darkness: The Prophecy (Disc 1) | PC | | Original | | CD-C95-166-0 | |
| Of Light and Darkness: The Prophecy (Disc 2) | PC | | Original | | CD-C95-166-1 | |
| Of Light and Darkness: The Prophecy (Disc 3) | PC | | Original | | CD-C95-166-2 | |
| Off-Road Redneck Racing | PC | | Original | | CD-C98-1259-0 | |
| Out of This World | PC | | Valueware | | CD-ICD-142-0 | |
| Omar Sharif on Bridge | PC | | Valueware | | CD-ICD-148-0 | |
| Out of This World | PC | | Rerelease | | CD-MMC-023-0 | |
| Odium ōdi·um | PC | | Original | | CD-W58-1104-0 | |
| The Operative: No One Lives Forever (Disc 1) | PC | | Bundle Version Micro-Star International OEM | | CD-W581995-MSYZ1, FXX08903223D1 | |
| The Operative: No One Lives Forever (Disc 2) (In the Lounge with No One Lives Forever) | PC | | Bundle Version Micro-Star International OEM | | CD-W581995-MSYZ2 | |
| Of Light and Darkness: The Prophecy (Disc 1) | PC | | Original | | CD-W95-166-E | |
| Of Light and Darkness: The Prophecy (Disc 2) | PC | | Original | | CD-W95-166-E | |
| Of Light and Darkness: The Prophecy (Disc 3) | PC | | Original | | CD-W95-166-E | |
| Original War (Disc 1) | PC | 1.02 | Original | | CD-W95-V006-IT1 | |
| Original War (Disc 2) | PC | 1.02 | Original | | CD-W95-V006-IT2 | |
| One Must Fall 2097 | PC | 2.1 | The Smile Edition | | CDR3016 | |
| The Oregon Trail | PC | 3.0.1 | Slash | | CDRM1239790 | |
| Operation Flashpoint: Elite | XBOX | | Original | | CM-090 | |
| Overlord | XBOX360 | | Original | | CM-2005 | |
| Overlord II | XBOX360 | | Original | | CM-2057 | |
| Operation Flashpoint: Dragon Rising | XBOX360 | | Original | | CM-2065 | |
| Operation Flashpoint: Dragon Rising | XBOX360 | | Original | | CM-2065 | |
| Operation Flashpoint: Red River | XBOX360 | | Original | | CM-2104 | |
| Operation Flashpoint: Red River | XBOX360 | | Original | | CM-2104 | |
| Oddballz: Your Wacky Computer Petz | PC | 1.0 | Original | | CS090370 | |
| One Must Fall 2097 One Must Fall | PC | | Rerelease | | D.L.: M-8684-97 | |
| O.D.T. | PC | | Dice | | DCG 005509 | |
| Overboard! | PC | | Dice | | DCG 005752, DMM 005776 | |
| Overboard! | PC | | Dice | | DCG 005752, DMM 005776 | |
| Oxide Oxyde | PC | | Dynamite | | DE-006 | |
| One Piece: Pirates Carnival ワンピース パイレーツカーニバル | GC | | Original | | DL-DOL-GIPJ-JPN | |
| Ohenro-San: Hosshin no Dojo (Awa Kuni) Hen お遍路さん 発心の道場 (阿波国) 編 | GC | | Original | | DL-DOL-GODJ-JPN | |
| Outlaw Golf | GC | | Original | | DL-DOL-GOFE-USA | |
| Outlaw Golf | GC | | Original | | DL-DOL-GOFP-EUR-01 | |
| One Piece: Grand Battle! 3 ONE PIECE ~グランド・バトル!3~ | GC | | Original | | DL-DOL-GOGJ-JPN | |
| Odama | GC | Rev 1 | Original | | DL-DOL-GOOE-USA | |
| Odama 大玉 | GC | Rev 1 | Bundled with Microphone | | DL-DOL-GOOJ-JPN | |
| Odama | GC | | Original | | DL-DOL-GOOP-EUR | |
| One Piece: Grand Battle! Rush ワンピース グラバト! ラッシュ | GC | | Original | | DL-DOL-GOPJ-JPN | |
| Open Season | GC | | Original | | DL-DOL-GOSE-USA | |
| Open Season | GC | | Original | | DL-DOL-GOSP-EUR | |
| Open Season | GC | | Original | | DL-DOL-GOSX-EUU | |
| Oneechanbara VorteX: Imichi o Tsugu Mono-tachi お姉チャンバラ vorteX ~忌血を継ぐ者たち~ | XBOX360 | | Original | | DP-2002 | |
| Onechanbara: Bikini Samurai Squad | XBOX360 | | Original | | DP-2026 | |
| Oneechanbara Z: Kagura お姉チャンバラZ~カグラ~ | XBOX360 | | Original | | DP-2036 | |
| Oddworld: La Fureur de l'Etranger Oddworld: Stranger's Wrath | XBOX | | Original | | EA-109 | |
| Oddworld: Stranger's Wrath | XBOX | | Original | | EA-109 | |
| Oddworld: Stranger's Wrath | XBOX | | Original | | EA-109 | |
| Oddworld: Strangers Vergeltung | XBOX | | Original | | EA-109 | |
| The Orange Box | XBOX360 | | Original | | EA-2063 | |
| The Orange Box | XBOX360 | | Original | | EA-2063 | |
| The Orange Box 오렌지 박스 | XBOX360 | | Original | | EA-2063 | |
| Offroad Off-Road Redneck Racing | PC | | Original | | ECD 000592K | |
| Ogallala: Das Kartenspiel für PC | PC | | Original | | ECD000799D 00031111-001 | |
| The Operational Art of War II | PC | 1.01.02 | Xplosiv | | EI-1259-3 | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.004 | Game of the Year Edition (Xplosiv) | | EI-1685-1 | |
| The Operative: No One Lives Forever (Disc 2) | PC | 1.004 | Game of the Year Edition (Xplosiv) | | EI-1685-2 | |
| One Must Fall 2097 | PC | | Original | | EPOMF01 | |
| One Must Fall 2097 | PC | | Original | | EPOMF01 | |
| Oil Tycoon 2 Oil Tycoon 2: Il Ritorno di una Leggenda | PC | | EXA Games | | EXAG020 | |
| Operation Flashpoint: Red River | PC | | Kakaku Kaiteihan | | FBG028W000A10 | |
| Orgazumi (Disc 1) オーガズミー | PC | | Original | | FCG013 | |
| Orgazumi (Disc 2) オーガズミー | PC | | Original | | FCG014 | |
| Of Orcs and Men | XBOX360 | | Original | | FE-2009 | |
| Otogi O・TO・GI ~御伽~ | XBOX | | Original | | FS-002 | |
| Otogi: Myth of Demons | XBOX | | Original | | FS-002 | |
| Otogi: Myth of Demons | XBOX | | Special Pack | | FS-002 | |
| Otogi: Myth of Demons | XBOX | | Original | | FS-002 | |
| Otogi 2: Immortal Warriors | XBOX | | Original | | FS-004 | |
| Otogi 2: Immortal Warriors | XBOX | | Original | | FS-004 | |
| Otogi: Hyakki Toubatsu Emaki O・TO・GI ~百鬼討伐絵巻~ | XBOX | | Special Pack | | FS-004 | |
| Ojousama Sousamou お嬢様捜査網 | PC-FX | | Original | | FXNHE616 | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.0 | Original | | FXX08903223D1 | |
| The Operative: No One Lives Forever (Disc 2) | PC | 1.0 | Original | | FXX08903223D2 | |
| The Operative: No One Lives Forever (Disc 2) | PC | 1.0 | Original | | FXX08903223D2 | |
| Off-World Interceptor オフ‐ワールド・インターセプター | 3DO | | Original | | FZ-SJ3151 | |
| Outer World アウター・ワールド | 3DO | | Original | | FZ-SJ3451 | |
| Oukoku no Grand Chef 王国のグランシェフ | 3DO | | Original | | FZ-SJ4252 | |
| Onee-san to Issho! Janken Paradise お姉さんといっしょ! じゃんけん パラダイス | 3DO | | Original | | FZ-SJ5251 | |
| Onee-san to Issho! Kisekae Paradise お姉さんといっしょ! 着せ替え パラダイス | 3DO | | Original | | FZ-SJ5252 | |
| Olympic Soccer | 3DO | | Original | | FZ-SW0011 | |
| Olympic Summer Games | 3DO | | Original | | FZ-SW0012 | |
| Omerta: City of Gangsters | PC | | Covermount | | G1DVD0215 | |
| Off-World Interceptor 혹성질주 | 3DO | | Original | | GDT-GA241 | |
| OutRun 2 | CHIHIRO | 2.000 | Original | | GDX-0004A | |
| Ollie King オーリーキング | CHIHIRO | 1.003 | Original | | GDX-0007 | |
| Otomedius (System Disc) オトメディウス | KEA | JAA | Original | | GGGJAA01 | |
| Otomedius (Application Disc 1) オトメディウス | KEA | JAA | Original | | GGGJAA02 | |
| Otomedius (Application Disc 2) オトメディウス | KEA | JAA | Original | | GGGJAA03 | |
| Omakase! Savers おまかせ!退魔業 | SS | 1.002 | Original | | GS-9030 | |
| Orgaslave (Side-1) オルガスレイブ | PC | | Original | | H PT 003-1 | |
| Orgaslave (Side-2) オルガスレイブ | PC | | Original | | H PT 003-2 | |
| Ookami-teki Monshou: Crest of Wolf 狼的紋章 クレスト・オブ・ウルフ | PCE | | Original | | HCD3044 | |
| Oregon Trail II | PC | 1.31 | Rerelease | | HCD744BE-CD | |
| Oogami Ichirou Funtou-ki: Sakura Taisen Kayou Show "Beni Tokage" yori (Disc 1) 大神一郎奮闘記 ~サクラ大戦歌謡ショウ「紅蜥蜴」より~ | DC | 1.000 | Original | | HDR-0057 | |