| Region | Title | System | Version | Edition | Languages | Serial | Status |
|---|
 | O Xephteris Taxideuei stin Ellada
Ο Ξεφτέρης ταξιδεύει στην Ελλάδα | 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 | | | |
| Obratnyj otschet
Обратный отсчет | PC | v.1 1.06.10.22 | Original | | | |
 | ObsCure (Disc 1)
惊悚空间 | PC | 1.0 | Original |  | | |
 | ObsCure | PC | | Original |   | | |
| ObsCure | PC | 1.0 | Original |  | 719 02 102 | |
 | ObsCure | PC | | Original |   | 71902134 | ![2 and more dumps from original media [!]](/images/status/green.png "2 and more dumps from original media [!]") |
| ObsCure | PC | | Best of Atari | | | |
 | ObsCure | PC | 1.1 | Covermount | | | |
| ObsCure (Disc 4) | PC | | Original | | | |
| ObsCure II | PC | | Original | | | |
| ObsCure II | PC | 1.0.0.0 | 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 | | | |
| Official Formula 1 Racing | PC | | Original | | | |
| Offroad
Off-Road Redneck Racing | PC | | Original | | ECD 000592K | |
| Oficery: Special'noe izdanie
Офицеры: Специальное издание | PC | 1.18.2 | Original | | | |
| Oktoberfest Wiesn-Gaudi | PC | 1.0 | Original | | | |
 | Olivers Äventyr: Drakens Förbannelse | PC | | Original |     | 021120110 | |
| Olympic Games: Atlanta 1996 | PC | | Original | | | |
| Olympic Soccer | PC | | Kixx | | | |
| Omerta: City of Gangsters | PC | | Covermount | | G1DVD0215 | |
 | 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 | | | |
| One Must Fall: Battlegrounds | PC | 2090 | Original | | | |
| One Must Fall: Battlegrounds | PC | 2090 | Original | | | |
| Oni | PC | 1.0 | Original | | | |
| 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 | | | |
 | Oozora ni Kodawarou! Minna no Kuukou 2
大空にこだわろう！ みんなの空港２ | PC | | |  | | |
| Open Season (Disc 1) | PC | 1.00 | Original |  | 5004904-CD 1 | |
| 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 (Disc 1) | PC | 1.00 | Original | | | |
| Open Season (Disc 1) | PC | 1.0 | Original | | 683131-CD1 | |
| Operaciya Bagration
Операция Багратион | PC | | Original | | | |
| Operaciya Silent Storm (Disc 1)
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 Flashpoint: Cold War Crisis | PC | 1.0 | Original | | MOPFCDEU00 | |
| Operation Flashpoint: Cold War Crisis | PC | 1.0 | Original, Gold Edition | | 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: Cold War Crisis | PC | | The Games Collection | | | |
| Operation Flashpoint: Cold War Crisis | PC | 1.0 | Original | | MOPFCDUS00 | |
| Operation Flashpoint: Dragon Rising | PC | 1.0 | Original | | MOFP2CDEU00 | |
| Operation Flashpoint: Dragon Rising | PC | | Original | | MOFP2CDEU00 | |
| Operation Flashpoint: Gold Upgrade | PC | 1.30 | Original | | MOFUCDUS00 | |
 | Operation Flashpoint: Gold Upgrade | PC | 1.30 | Original, Gold Edition | | MOFUCDEU00, MOFUCDUS00 | |
| Operation Flashpoint: Holodnaja vojna
Операция Flashpoint: Холодная война | PC | 1.46 | Original | | | |
| Operation Flashpoint: Red River | PC | 1.0 | Original | | MOFP3CDEU00 | |
| Operation Flashpoint: Red River | PC | | Kakaku Kaiteihan | | FBG028W000A10 | |
| Operation Flashpoint: Red River | PC | | Original | | MOFP3CDUS00 | |
| Operation Flashpoint: Resistance | PC | 1.75 | Original | | MOFRCDEU00 | |
| Operation Flashpoint: Resistance | PC | 1.75 | Original | | MOFRCDUS00 | |
| 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 | Original | | FXX08903223D1 | |
| 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 | 1.004 | Game of the Year Edition | | S0025037 | |
| 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 1) | PC | 1.0 | Original | | | |
 | Opowieści z Narnii: Lew, Czarownica i Stara Szafa (Disc 1) | PC | | Original |  | | |
| The Orange Box (Disc 1) | PC | | Original |    | VAX07705811D | |
| The Orange Box (Disc 1) | PC | | Original | | VAD07705811D | |
| The Orange Box (Disc 2) | PC | | Original | | VAD07705811D2 | |
| The Orange Box (Disc 1) | PC | | Original | | VAI07705811D | |
| The Orange Box (Disc 2) | PC | | Original | | VAI07705811D2 | |
| 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 | | Original | | | |
 | The Orange Box (Disc 1)
戰慄時空2：二部曲重裝旗艦版 | PC | | Original | | TTE0193 | |
| The Orange Box (Disc 2)
戰慄時空2：二部曲重裝旗艦版 | PC | | Original | | TTE0193 | |
| The Orange Box (Disc 2) | PC | | Original | | 985217 | |
| The Orange Box (Disc 1) | PC | | Original, EA Classics | | 985207, VAE07705811D, VAE07705811D/ENG, VAE07707118D/ENG, VAX07705811D/AUS | |
 | The Orange Box (Disc 2) | PC | | Original, EA Classics | | VAE07705811D2/ENG, VAE07707118D2/ENG, VAX07705811D2, VAX07705811D2/AUS | |
| Order of War: Osvobozhdenie
Order of War: Освобождение | PC | | Igromaniya: Vybor redakcii | | | |
| Order of War: Stolknovenie
Order of War: Столкновение | PC | | Igromaniya: Vybor redakcii | | | |
| Ore no Shita de Agake
俺の下であがけ | PC | System3.9 Ver.5.43 | Original | | ALB-005 | |
| The Oregon Trail 3rd Edition: Pioneer Adventures | PC | 1.0 | DVD-ROM | | ORG811AE-DVD | |
 | Ori and the Blind Forest: Definitive Edition | PC | 5.3.2.9582331 | Limited Edition | | | |
| Original War (Disc 2) | PC | 1.02 | Original | | CD-W95-V006-IT2 | |
| Orion Burger | PC | | Original | | | |
| Outcast (Disc 2) | PC | | Original | | OUTCAPC52G/A2 | |
| Outcast (Disc 2) | PC | | Limitierte Sonderausgabe | | OUTCAPC520/A2 | |
| Outcast (Disc 2) | PC | | Original | | 42831-9110TC | |
| The Outforce | PC | 1.0.0.0 | Original | | | |
| Outlaw Golf | PC | | Original | | RM-OUTGOLF-UK | |
| Outlaws (Disc 1) | PC | 1.1 | Rerelease | | | |
| Outlive | PC | 1.01 | Original | | | |
| OutRun 2006: Coast 2 Coast | PC | | Gamer's Choice | | THQ70690 | |
| 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 | 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 | |
 | OutRun 2006: Coast 2 Coast | PC | | Top Games | | SEGA-PC029 | |
| OutRun 2006: Coast 2 Coast (Disc 1) | PC | | Original | | | |
| Outward | PC | | Day One Edition | | 1024669LAINT, 103699 | |
| Overclocked: Una Storia di Violenza | PC | 1.1 | Original | | | |
| Overlord | PC | | Original | | MOVL1CDEU00 | |
| Overlord | PC | 1.2 | Original | | MOVL1CDPL00 (DVD), POVL1CDPL03 (Box) | |
| Overlord
BGamer 153 (Side A) | PC | | Covermount | | | |
| Overlord | PC | 1.2 | Original | | | |
| Overlord II | PC | | Original | | MOVL2CDEU00 | |
| Overlord II | PC | | Original | | | |
| Overlord II | PC | | Preview Code |  | | |
| Overlord: Raising Hell | PC | 1.3 | Original | | MOVLRCDEU00 | |
| Overlord: Raising Hell | PC | 1.3 | Original | | | |
| Overwatch | PC | | Game of the Year Edition, Legendary Edition | | 73052010US, S7302210 | |
 | Overwatch | PC | | Origins Edition | | | |
