Region | Title | System | Version | Edition | Languages | Serial | Status |
| Official Sega Dreamcast Magazine Vol. 3: January 2000 | DC | 1.010 | | | IGN2 | |
| Official Sega Dreamcast Magazine Vol. 2: November 1999 | DC | 1.020 | | | IGN1 | |
| Official Sega Dreamcast Magazine Vol. 11: February 2001 | DC | 0.500 | | | | |
| Official Sega Dreamcast Magazine Vol. 10: January 2001 | DC | 1.200 | | | IGN10 | |
| Official Lara Croft: Real Life '99 Lara: Character Images | PC | | Press Kit | | | |
| The Official Guide to The Daedalus Encounter: Companion Disc | PC | | Original | | | |
| The Official Guide to Babylon 5 The Official Guide to J. Michael Straczynski's Babylon 5 | PC | | Original | | | |
| Official Duke Nukem 3D Level Design Handbook | PC | | Original | | 1869-0 | |
| The Official Browser of Primagames.com | PC | | | | | |
| The Office | PC | | Original | | | |
| Off-World Interceptor Extreme | SS | 1.000 | Original | | T-15908H | |
| Off-World Interceptor Extreme | PSX | | Original | | SLUS-00020 | |
| Off-Road Redneck Racing | PC | | Original | | CD-C98-1259-0 | |
| Of Light and Darkness: The Prophecy (Disc 3) | PC | | Original | | CD-C95-166-2 | |
| Of Light and Darkness: The Prophecy (Disc 2) | PC | | Original | | CD-C95-166-1 | |
| Of Light and Darkness: The Prophecy (Disc 1) | PC | | Original | | CD-C95-166-0 | |
| Odyssey: The Search for Ulysses (Disc 2) | PC | | Original | | | |
| Odyssey: The Search for Ulysses (Disc 1) | PC | | Original | | | |
| Odyssey: The Legend of Nemesis | MAC | 1.0 | Original | | | |
| ODS Robot Challenge | PC | 5.0.1r26 | Teacher's Edition | | | |
| ODS Robot Challenge | PC | | Original | | | |
| ODS Carnival Math | PC | 5.0r134 | Teacher's Edition | | | |
| ODS Carnival Math | PC | 5.0r134 | Teacher's Edition | | | |
| ODS Amazing Art Corner | PC | 5.0r134 | Teacher's Edition | | | |
| ODS Air Explorer | PC | 5.0r134 | Teacher's Edition | | | |
| ODS Air Explorer | PC | 5.0r134 | Teacher's Edition | | | |
| Odium ōdi·um | PC | | Original | | CD-W58-1104-0 | |
| Odin Sphere: Leifthrasir | PS3 | 01.01 | Original | | BLUS-31601 | |
| Odin Sphere | PS2 | 1.00 | Trade Demo | | SLUS-28065 | |
| Odin Sphere | PS2 | 1.00 | Original, Greatest Hits | | SLUS 21577 … | |
| Odell Down Under | PC | | Original, SoftKey | | POD544AE-CD | |
| Oddworld: Stranger's Wrath HD | PS3 | 01.00 | Original | | BLUS-31620 | |
| Oddworld: Stranger's Wrath | XBOX | | Original | | EA-109 | |
| Oddworld: Munch's Oddysee | XBOX | | Platinum Hits | | MS-001 | |
| Oddworld: Abe's Origins | PC | | Limited Run Games | | | |
| Oddworld: Abe's Oddysee: New 'n' Tasty! | PS3 | 01.00 | Limited Edition | | BLUS-31621 | |
| Oddworld: Abe's Oddysee | PSX | Rev 2 | Greatest Hits | | SLUS-00190 | |
| Oddworld: Abe's Oddysee | PSX | Rev 1 | Original, Greatest Hits | | SLUS-00190 | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Original | | 04-12608CD | |
| Oddworld: Abe's Oddysee | PC | 2.0 | Channelware | | 04-15303 | |
| Oddworld: Abe's Oddysee | PSX | | Trade Demo | | | |
| Oddworld: Abe's Oddysee | PSX | | Original | | SLUS-00190 | |
| Oddworld: Abe's Oddysee | PSX | | Demo | | SLUS-90004 | |
| Oddworld: Abe's Exoddus (Disc 2) | PSX | | Original | | SLUS-00731 … | |
| Oddworld: Abe's Exoddus (Disc 1) | PSX | | Original | | SLUS-00710 … | |
| Oddworld: Abe's Exoddus (Install) | PC | 2.0 | Original | | 04-15993CD1 | |
| Oddworld: Abe's Exoddus (Play) | PC | | Original | | 04-15993CD2 | |
| Odama | GC | Rev 1 | Original | | DL-DOL-GOOE-USA | |
| Octomania | WII | | Original | | RVL-RTKE-USA | |
| Oceans Below | PC | | Bundle Version OEM | | RVL 13-004-059 Rev. A / 2198610-590002 / I 083100 | |
| Oceans Below | 3DO | | Original | | | |
| Oceans Below The Software Toolworks Presents ... Oceans Below | MAC | | Original | | 2198620-590001 / I 073100, CDRM1103420 | |
| Ocean Commander | WII | | Original | | RVL-RQME-USA | |
| Obsidian (Disc 5) | PC | | Original | | 11008 | |
| Obsidian (Disc 5) | PC | | Original, Complimentary Copy | | 11008 | |
| Obsidian (Disc 4) | PC | | Original, Complimentary Copy | | 11008 | |
| Obsidian (Disc 3) | PC | | Original, Complimentary Copy | | 11008 | |
| Obsidian (Disc 2) | PC | | Original, Complimentary Copy | | 11008 | |
| Obsidian (Disc 1) | PC | | Original | | 11008 | |
| Obsidian (Disc 1) | PC | | Original, Complimentary Copy | | 11008 | |
| Obsidian | PC | 1.0 | Demo | | | |
| ObsCure: The Aftermath | PSP | 1.00 | Original, Test Sample | | ULUS-10484 | |
| ObsCure: The Aftermath | PS2 | 1.00 | Original | | SLUS-21709 | |
| ObsCure: The Aftermath | WII | | Original | | RVL-ROBE-USA | |
| ObsCure: The Aftermath | WII | | Beta | | | |
| ObsCure (Disc 5) | PC | 1.0 | Original | | PCO457CD | |
| ObsCure (Disc 4) | PC | 1.0 | Original | | PCO457CD | |
| ObsCure (Disc 3) | PC | 1.0 | Original | | PCO457CD | |
| ObsCure (Disc 2) | PC | 1.0 | Original | | PCO457CD | |
| ObsCure (Disc 1) | PC | 1.0 | Original | | PCO457CD | |
| ObsCure | PS2 | 1.00 | Original | | SLUS 20777 | |
| ObsCure | XBOX | | Original | | MI-009 | |
| Obduction | PC | 1.4.2 | Kickstarter | | | |
| Obduction | MAC | | Kickstarter | | | |
| O.R.B: Off-World Resource Base | PC | 1.0 | Original | | 22434CD | |
| O.D.T. | PSX | | Original | | SLUS-00698 | |
| O.D.T. | PSX | | Demo | | SLUS-90043 | |