Region | Title | System | Version | Edition | Languages | Serial | Status |
| O Xephteris Taxideuei stin Ellada Ο Ξεφτέρης ταξιδεύει στην Ελλάδα | PC | | Original | | | |
| O! Rety! Psoty Dudusia Wesołka | PC | | Playada Gier | | P_20265_03A_PL | |
| O.D.T. | PC | | Dice | | DCG 005509 | |
| 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 | | | |
| 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 | | | |
| Obratnyj otschet Обратный отсчет | PC | v.1 1.06.10.22 | Original | | | |
| Obrońca | PC | | FajnaGra.pl | | | |
| Obscure ObsCure | PC | | Original | | | |
| Obscure ObsCure | PC | 1.0 | Original | | 719 02 102 | |
| Obscure ObsCure | PC | | Best of Atari | | | |
| Obscure ObsCure | PC | 1.1 | Covermount | | | |
| Obscure (Disc 1) ObsCure | PC | | Original | | | |
| Obscure (Disc 2) ObsCure | PC | | Original | | | |
| Obscure (Disc 3) ObsCure | PC | | Original | | | |
| Obscure (Disc 4) ObsCure | PC | | Original | | | |
| Obscure II ObsCure II | 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 | | | |
| Ocean/Infogrames Show Case December 1997 | PC | | | | | |
| Oct 15 2002 | PC | | Press Kit | | | |
| 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 Exoddus (Installatie Disk) | PC | 2.0 | Budget | | MMICDR 5280 | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Covermount | | IB2G-ODDI5 | |
| Oddworld: L'Odyssée d'Abe | PC | | Original | | IB2G-ODDF5 | |
| Odens Öga Odens Öga! | PC | 1.0.0 | Original | | | |
| Odin Klik Один Клик | PC | | Original | | 301/2002 | |
| Odissea: Sulle tracce di Ulisse (Disc 1) | PC | | Original | | ODY-ITA-P01 | |
| Odissea: Sulle tracce di Ulisse (Disc 2) | PC | | Original | | ODY-ITA-P02 | |
| 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 | | | |
| Odyssee: Auf der Suche nach Odysseus (Disc 1) | PC | | Original | | ODY-GERCD1 | |
| Odyssee: Auf der Suche nach Odysseus (Disc 2) | PC | | Original | | ODY-GERCD2 | |
| Odysseia ΟΔΥΣΣΕΙΑ | PC | 1.8 | Original | | | |
| 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 | |
| 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 Limits: Cassiopeia | PC | | ROMWARE | | ROM 10100 | |
| Off Limits: Mizar | PC | | ROMWARE | | ROM 10120 | |
| Offensive | PC | | Original | | | |
| Offensive Offensive War: The Ultimate Strategical Combat Game | PC | | Covermount | | | |
| Offroad Off-Road Redneck Racing | PC | | Original | | OFFPCCDML | |
| Offroad Off-Road Redneck Racing | PC | | Original | | ECD 000592K | |
| Offroad Extreme! Special Edition | PC | | Original | | | |
| Oficery: Special'noe izdanie Офицеры: Специальное издание | PC | 1.18.2 | Original | | | |
| Ogallala: Das Kartenspiel für PC | PC | | Original | | ECD000799D 00031111-001 | |
| Ognisty Podmuch: Fire Captain (Disc 1) (Dysk Instalacyjny) | PC | | Covermount | | | |
| Ognisty Podmuch: Fire Captain (Disc 2) (Dysk z Grą) | PC | | Covermount | | | |
| Oil Platform Simulator | PC | 1.0 | Original | | | |
| Oil Rush | PC | | Original | | | |
| Oil Tycoon | PC | 1.0 | Original | | | |
| Oil Tycoon 2 | PC | | Original | | | |
| Oil Tycoon 2 Oil Tycoon 2: Il Ritorno di una Leggenda | PC | | EXA Games | | EXAG020 | |
| 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 | | | |
| Oksfordzka Encyklopedia Historii Świata. Tom II | PC | | Covermount | | SELL 0108 | |
| Oktoberfest Wiesn-Gaudi | PC | 1.0 | Original | | | |
| Oldtimer: Erlebte Geschichte Teil II | PC | | Original | | | |
| Olimpiada Zimowa 2002 Olimpijskie Zmagania 2002 | PC | | Original | | | |
| Olivers Äventyr: Drakens Förbannelse | PC | | Original | | 021120110 | |
| Ollo en de Reuzentomaat | PC | | CD-ROM Topper | | | |
| Ollo in the Sunny Valley Fair | PC | | Original | | | |
| Olympic Games: Atlanta 1996 | PC | | Original | | | |
| Olympic Soccer | PC | | Kixx | | | |
| Olympic Soccer | PC | | CD-ROM Classic Collection 2 | | | |
| The Omega Stone: Secrets of the Ancients (Disc 1) | PC | | Original | | OMSTENCD1 | |
| The Omega Stone: Secrets of the Ancients (Disc 2) | PC | | Original | | OMSTENCD2 | |
| The Omega Stone: Secrets of the Ancients (Disc 3) | PC | | Original | | OMSTENCD3 | |
| The Omega Stone: Secrets of the Ancients (Disc 4) | PC | | Original | | OMSTENCD4 | |
| Omerta: City of Gangsters | PC | | Covermount | | G1DVD0215 | |
| Omikron: The Nomad Soul | PC | | Promo | | | |
| Omnia Junior 1: Enciclopedia: Dizionario | PC | | Covermount | | SIAE 08A01PA | |
| Omnia Junior 2: Storia: Attività interattive | PC | | Covermount | | SIAE 0901PA | |
| Omnia Junior 3: Il Mondo degli Animali | PC | | Covermount | | SIAE1001PA | |
| OMSI Add-on: Wien: Der Hochflurbus LU 200 | PC | 1.0 | OMSI Bundle | | | |
| 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 | | | |
| Ona: Sbornik e'roticheskix igr Она: Сборник эротических игр | PC | | Original | | 10-20999 | |
| One Must Fall 2097 One Must Fall 2097 CD-ROM | PC | 1.1 | ROMWARE | | ROM 10017 | |
| One Must Fall 2097 | PC | 2.1 | The Smile Edition | | CDR3016 | |
| One Must Fall 2097 | PC | | Demo: JukeBox Collection | | | |
| One Must Fall 2097 | PC | | Original | | | |
| One Must Fall 2097 One Must Fall | PC | | Rerelease | | D.L.: M-8684-97 | |
| One Must Fall: Battlegrounds | PC | 2090 | Original | | | |
| One Step Beyond | PC | | Hit Squad: Regenerator | | | |
| Oni | PC | 1.0 | Original | | | |
| Oni | PC | 1.0 | Covermount | | | |
| Oni | PC | 1.0 | Covermount | | | |
| Oni | PC | 1.0 | PC Best Buy | | 177588 | |
| Onible'jd Ониблэйд | PC | | Original | | | |
| Onimusha 3 | PC | | Original | | 5004561 | |
| 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 | | | |
| Online G@mer n. 5: Juin/Juillet 2001 (Disc 1) | PC | | | | | |
| OnlineGamez | PC | | | | | |
| Only Fun: Entra anche tu nel mondo dei Videogames | PC | | | | | |
| Onsalakorv | PC | | Original | | | |
| 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 | |
| Open Season Boog & Elliot | PC | 1.0 | Demo | | | |
| Open Season (Disc 1) | PC | 1.00 | Original | | | |
| Opera Fatal | PC | | Tandem | | 1444 | |
| Opera Fatal | PC | | Original | | | |
| Operaciya "Barbarossa" Операция "Барбаросса" | PC | | Original | | | |
| Operaciya "Blau" Операция "Блау" | PC | | Original | | | |
| Operaciya "Plastilin" (Disc 1) Операция "Пластилин" | PC | | Original | | | |
| Operaciya "Plastilin" (Disc 2) Операция "Пластилин" | PC | | Original | | | |
| Operaciya "X" ili novye piklyucheniya Shuricha (Disc 1) Операция "Х" или новые приключения Шурича | PC | | 1C: Kollekciya igrushek | | | |
| 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 Barbarossa: The Struggle for Russia | PC | | Original | | | |
| Operation Flashpoint: Cold War Crisis | PC | 1.0 | Original | | MOPFCDEU00 | |
| Operation Flashpoint: Cold War Crisis | PC | 1.46 | Sold Out Software | | | |
| Operation Flashpoint: Cold War Crisis | PC | 1.46 | Sold Out Software | | | |
| Operation Flashpoint: Dragon Rising | PC | 1.0 | Original | | MOFP2CDEU00 | |
| Operation Flashpoint: Dragon Rising | PC | | Original | | MOFP2CDEU00 | |
| Operation Flashpoint: Gold Upgrade Operace Flashpoint: Gold Upgrade | PC | | Original | | | |
| Operation Flashpoint: Red River | PC | 1.0 | Original | | MOFP3CDEU00 | |
| Operation Flashpoint: Soprotivlenie Operation Flashpoint: Сопротивление | PC | 1.85 | | | | |
| Operation Mittelmeer | PC | | Original | | | |
| Operation Neptun | PC | 1.2 | Original | | ONT844AW-CD | |
| Operation Thunderstorm | PC | 1.0 | Original | | | |
| Operation: Surgery Has Never Been so Silly! | PC | | Replay Kids | | OPERPCREGB/A | |
| Operation: Surgery Has Never Been so Silly! | PC | | Sold Out Software | | | |
| The Operational Art of War II | PC | 1.01.02 | Xplosiv | | EI-1259-3 | |
| The Operational Art of War II: 1956-2000 The Operational Art of War II: Bewaffnete Konflikten | PC | | Original | | | |
| 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 | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.004 | Game of the Year Edition | | S0025036 | |
| The Operative: No One Lives Forever (Disc 2) | PC | 1.0 | Original | | FXX08903223D2 | |
| The Operative: No One Lives Forever (Disc 2) | PC | 1.004 | Game of the Year Edition | | S0025037 | |
| 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 | | | |
| The Orange Box (Disc 1) | PC | | Original | | VAD07705811D | |
| The Orange Box (Disc 2) | PC | | Original | | VAD07705811D2 | |
| 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 | | | |
| 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 | | | |
| Original War (Disc 1) | PC | | Original | | | |
| Original War (Disc 2) | PC | | Original | | | |
| Original War (Disc 1) | PC | 1.02 | Covermount | | | |
| Original War (Disc 1) | PC | 1.02 | Original | | CD-W95-V006-IT1 | |
| Original War (Disc 2) | PC | 1.02 | Covermount | | | |
| Original War (Disc 2) | PC | 1.02 | Original | | CD-W95-V006-IT2 | |
| Orion Burger | PC | | Original | | | |
| Orion Burger | PC | | Abenteuer Doppelpack: Premier Collection | | MOBRLPGE72 | |
| Orly Pervoj mirovoj Орлы Первой мировой | PC | 02.19.07 | Original | | | |
| Oro e Gloria: La Strada per El Dorado | PC | | Covermount | | | |
| Ortofrajda | PC | | | | | |
| Osada Avalona (Disc 1) Осада Авалона | PC | | | | | |
| Osada Avalona (Disc 2) Осада Авалона | PC | | | | | |
| Oscar | PC | | Golden Zone | | | |
| Oscar der Ballonfahrer und die Geheimnisse des Waldes | PC | | | | | |
| Osef Minei Mischakim אוסף מיני משחקים | 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 | | | |
| Othello CD-ROM | PC | | Original | | | |
| Otto's Ottifanten | PC | | Original | | | |
| Otverzhennye: Tajna temnoj rasy (Disc 2) Отверженные: Тайна темной расы | PC | | 1C: Igrushki | | SNOW OT21 0110 IR | |
| Our Worst Fears: Die Blumen des Todes | PC | | Original | | | |
| Outbreaker | PC | | Original | | | |
| Outcast (Disc 1) | PC | | Original | | OUTCAPC52F/A1 | |
| Outcast (Disc 1) | PC | | Play the Games Vol. 3 | | | |
| Outcast (Disc 1) | PC | | Limitierte Sonderausgabe | | OUTCAPC520/A1 | |
| Outcast (Disc 2) | PC | | Limitierte Sonderausgabe | | OUTCAPC520/A2 | |
| Outcast (Disc 2) | PC | | Play the Games Vol. 3 | | | |
| Outcast (Disc 3) | PC | | Limitierte Sonderausgabe | | OUTCAPC520/A3 | |
| Outer Ridge | PC | 1.0 | Original | | SPI004 | |
| The Outforce | PC | 1.0.0.0 | Original | | | |
| Outlaw Golf | PC | | Original | | RM-OUTGOLF-UK | |
| Outlaw Racers | PC | | Sold Out Software | | | |
| Outlaws (Disc 1) | PC | 2.0 | Collection LucasArts | | | |
| Outlaws (Disc 2) | PC | 2.0 | Collection LucasArts | | | |
| Outlaws (Disc 1) | PC | 1.1 | Rerelease | | | |
| Outlaws (Disc 2) | PC | 1.1 | Rerelease | | | |
| Outlaws (Disco 1) | PC | 1.0 | LucasArts Classic | | 41175.101.IT | |
| Outlaws (Disco 2) | PC | 1.0 | LucasArts Classic | | 41175.102.IT | |
| Outlaws: Die Gesetzlosen (Disc 1) | PC | 1.1.1 | Original | | | |
| Outlaws: Die Gesetzlosen (Disc 2) | PC | 1.1.1 | Original | | | |
| Outpost | PC | | Original | | S390021012ZZ2 | |
| Outpost | PC | | SierraOriginals | | S4941220Z12Z2 | |
| Outpost | PC | | Original | | S 390121012ZZZ | |
| Outpost | PC | 1.51 | Schweinepreise | | S390122CZ12ZZ | |
| Outpost 2: Destini Sospesi | PC | 1.0 | Covermount | | | |
| Outpost 2: Divided Destiny | PC | | SierraOriginals | | | |
| Outpost 2: Divided Destiny | PC | 1.0 | Original | | S0011246 | |
| Outrage | PC | | Original | | | |
| OutRun 2006: Coast 2 Coast | PC | | GSP White Label: Reload | | 1673A | |
| OutRun 2006: Coast 2 Coast | PC | | White Label | | 1673A | |
| OutRun 2006: Coast 2 Coast | PC | | Top Games | | SEGA-PC029 | |
| Outwars (Disc 1) | PC | 1.0 | Original | | 0398 Artikelnr. X00-14039 DE | |
| Outwars (Disc 2) | PC | 1.0 | Original | | 0398 Artikelnr. X00-14040 DE | |
| Ovech'i bega Овечьи бега | PC | 1.0 | Original | | | |
| Over 350 Jigsaw Puzzles | PC | | Original | | 012163 | |
| Over 350 Solitaire Games | PC | | Original | | | |
| Over Load | PC | | | | | |
| Overboard! | PC | | Dice | | DCG 005752, DMM 005776 | |
| Overclocked: Una Storia di Violenza | PC | 1.1 | Original | | | |
| OverKill | PC | | ROMWARE | | ROM 10 007 | |
| Overlord | PC | | Original | | MOVL1CDEU00 | |
| Overlord | PC | 1.2 | Original | | MOVL1CDPL00 (DVD), POVL1CDPL03 (Box) | |
| Overlord BGamer 153 (Side A) | PC | | Covermount | | | |
| Overlord II | PC | | Original | | MOVL2CDEU00 | |
| Overlord II | PC | | Original | | | |
| Overlord: Raising Hell | PC | 1.3 | Original | | MOVLRCDEU00 | |
| Overlord: Raising Hell | PC | 1.3 | Original | | | |
| Overwatch | PC | | Origins Edition | | 052429 | |
| The Oxfordshire Golf Club | PC | | Original | | EAE05101006D | |
| Oxide Oxyde | PC | | Dynamite | | DE-006 | |
| Oxyd Magnum! Gold Edition | PC | | Game-Pack 3 | | 80227 | |
| Oynayarak Ogreniyorum 1 Oynayarak Öğreniyorum 1 | PC | | Original | | | |
| Oyungezer: Mart 2010 | PC | | | | | |
| Oyunlarla Dil Bilgisi Oyunlarla Matematik | PC | | Original | | | |
| O.D.T. | PC | | Original | | | |
| Ob"ekt 69: Kasablanka Объект 69: Касабланка | PC | | Original | | RUSSOBIT-M 2003/408 | |
| Ob"ekt 69: Mest' Krassera Объект 69: Месть Крассера | PC | | Original | | | |
| Obscure ObsCure | PC | | Original | | 71902134 | |
| Obscure ObsCure | PC | | Software Pyramide | | | |
| Obscure II ObsCure II | PC | 1.0 | Covermount | | | |
| Obscure II 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 | | | |
| Oddballz: Your Wacky Computer Petz | PC | 1.0 | Original | | CS090370 | |
| Oddworld: Abe's Exoddus (Play Disc) | PC | 2.0 | Budget, Covermount | | MMICDR 5280 | |
| Oddworld: Abe's Exoddus (Install Disc) | PC | 2.0 | Original | | | |
| Oddworld: Abe's Exoddus (Play Disc) | PC | 2.0 | Original | | | |
| Oddworld: Abe's Exoddus (Installazione) | PC | 1.0 | Replay | | ABEXPCREI/A1 | |
| Oddworld: Abe's Exoddus (Gioco) | PC | 1.0 | Replay | | ABEXPCREI/A2 | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Original | | IB2G-ODD5 | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Original | | IB2G-ODDG5 | |
| Odyssey: The Search for Ulysses (Disc 1) | PC | | Original | | ODY-ENCD1 | |
| Odyssey: The Search for Ulysses (Disc 2) | PC | | Original | | ODY-ENCD2 | |
| Official Formula 1 Racing | PC | | Original | | | |
| Oksfordzka Encyklopedia Historii Świata | PC | | Covermount | | SELL 0103 | |
| Oni Они | PC | 1.0 | | | | |
| Open Kart | PC | | I Videogiochi del "Giornalino" | | | |
| Open Season (Disc 1) | PC | 1.00 | Original | | 5004904-CD 1 | |
| Operation Flashpoint: Cold War Crisis | PC | 1.0 | Original, Gold Edition | | MOPFCDEU00 | |
| Operation Flashpoint: Cold War Crisis | PC | | The Games Collection | | | |
| Operation Flashpoint: Holodnaja vojna Операция Flashpoint: Холодная война | PC | 1.46 | Original | | | |
| Operation Flashpoint: Resistance | PC | 1.75 | Original | | MOFRCDEU00 | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.0 | Original | | FXX08903223D1 | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.004 | Game of the Year Edition (BestSeller Series) | | S0026178 | |
| The Operative: No One Lives Forever (Disc 2) | PC | 1.0 | Original | | FXX08903223D2 | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.004 | Game of the Year Edition (BestSeller Series) | | JCPL11, S0026695 | |
| The Operative: No One Lives Forever (Disc 1) | PC | 1.0.0.4 | Game of the Year Edition (Covermount) | | | |
| The Orange Box (Disc 1) | PC | | Original | | VAX07705811D | |
| The Orange Box (Disc 1) | PC | | Original | | VAI07705811D | |
| The Orange Box (Disc 2) | PC | | Original | | VAI07705811D2 | |
| Die Original Moorhuhn Jagd | PC | | Best of Moorhuhn | | | |
| Orion Burger | PC | | Gold Games 2 (CD 11) | | SPI 046 | |
| Oscar | PC | | Original | | | |
| Oscar | PC | | Jackson Libri | | | |
| Othello | PC | | Original | | | |
| Otorva v shkole Оторва в школе | PC | | Original | | | |
| Otverzhennye: Tajna temnoj rasy (Disc 1) Отверженные: Тайна темной расы | PC | | 1C: Igrushki | | SNOW OT21 0110 IR | |
| Outcast | PC | | Original | | | |
| Outcast (Disc 1) | PC | | Original | | OUTCAPC52G/A1 | |
| Outcast (Disc 2) | PC | | Original | | OUTCAPC52G/A2 | |
| Outcast (Disc 1) | PC | | Covermount | | | |
| Outcast (Disc 2) | PC | | Covermount | | | |
| Outlaws (Disc 1) | PC | 1.0 | Original | | 9511830 | |
| Outlaws (Disc 1) | PC | 2.0 | LucasArts Classics | | 3000009.101.UK | |
| Outlaws (Disc 2) | PC | 1.0 | Original | | 9511831 | |
| Outlaws (Disc 2) | PC | 2.0 | LucasArts Classics | | 3000009.102.UK | |
| Outlaws (Disc 1) | PC | | Original | | | |
| Outlaws (Disc 1) | PC | | M6 Multimedia | | M6IMM6 | |
| Outlaws (Disc 2) | PC | | Original | | | |
| Outlaws (Disc 2) | PC | | M6 Multimedia | | M6IMM6 | |
| Outlaws (Disc 1) | PC | 1.0 | Original | | | |
| Outlaws (Disc 2) | PC | 1.0 | Original | | | |
| Outlaws (Disco 1) | PC | 2.0 | Collezione CD-Rom by C.T.O. | | LUC628 | |
| Outlaws (Disco 2) | PC | 2.0 | Collezione CD-Rom by C.T.O. | | LUC628 | |
| Outlive | PC | 1.01 | Original | | | |
| Outpost 2: Geteilte Bestimmung | PC | 1.0 | Original | | S0011248 | |
| OutRun 2006: Coast 2 Coast | PC | | Gamer's Choice | | THQ70690 | |
| OutRun 2006: Coast 2 Coast | PC | 1.0 | Original | | SEGA-PC029 | |
| OutRun 2006: Coast 2 Coast | PC | 1.00.0000 | Serie Maxima II | | SEGA-PC029 | |
| OutRun 2006: Coast 2 Coast | PC | | eXtra Klasyka XK HIT | | TS OCC PL | |
| Outward | PC | | Day One Edition | | 1024669LAINT, 103699 | |
| Outwars (Disc 1) | PC | 1.0 | Original | | 0298 Part No. X03-63527 | |
| Outwars (Disc 2) | PC | 1.0 | Original | | 0298 Part No. X03-57509 | |
| Overboard! | PC | | Original | | | |
| Overboard! | PC | | Dice | | DCG 005752, DMM 005776 | |
| Overlord | PC | 1.2 | Original | | | |