 | Obitus Game Details | Screens | BulletProof | |  |
 | Obscure II Game Details | Screens | Playlogic | |  |
 | Octomania Game Details | Screens | Midas | |  |
 | Odama Game Details | Review | Preview | Screens | Nintendo | 7/10 |  |
 | Oddworld: Abe's Oddysee Game Details | Review | Screens | GT Interactive | 9/10 |  |
  | Ogre Battle 64: Person of Lordly Caliber Game Details | Review | Screens | Square Enix | 8/10 |  |
  | Ogre Battle: The March of the Black Queen Game Details | Screens | Black Pearl | |  |
 | OK! Puzzle Stars Game Details | Screens | Ubisoft | |  |
 | On the Ball Game Details | Screens | Taito | |  |
 | One Piece: Gear Spirit Game Details | Screens | Namco Bandai | |  |
 | One Piece: Gigant Battle! Game Details | Screens | Namco Bandai | |  |
 | One Piece: Unlimited Adventure Game Details | Screens | Namco Bandai | |  |
 | One Piece: Unlimited Cruise 1: The Treasure Beneath the Waves Game Details | Screens | Namco Bandai | |  |
 | Onechanbara: Bikini Zombie Slayers Game Details | Screens | D3 Publisher | |  |
  | Onimusha Tactics Game Details | Screens | Capcom | |  |
 | Oops! Game Details | Screens | Hudson | |  |
 | Open Season Game Details | Screens | Ubisoft | |  |
 | Operation Europe: Path to Victory 1939-45 Game Details | Screens | Koei | |  |
 | Operation Logic Bomb: The Ultimate Search & Destroy Game Details | Screens | Jaleco | |  |
 | Operation Thunderbolt Game Details | Screens | Taito | |  |
 | Opoona Game Details | Review | Preview | Screens | Koei | 7/10 |  |
 | Orcs and Elves Game Details | Review | Screens | EA | 8/10 |  |
 | Order! Game Details | Screens | Poisoft | |  |
  | Ordyne Game Details | Screens | NEC Avenue | |  |
 | Oscar Game Details | Screens | Titus | |  |
 | Oshare Majo Love and Berry: DS Collection Game Details | Screens | SEGA | |  |
 | Osu! Tatakae! Ouendan Game Details | Review | Screens | Nintendo | 9/10 |  |
  | Otogirisou Game Details | Screens | Chun Soft | |  |
 | Ougon no Kizuna Game Details | Screens | Jaleco | |  |
  | Out Live Game Details | Screens | SunSoft | |  |
 | Out of Galaxy Koshika Game Details | Screens | SunSoft | |  |
 | Out Run Game Details | Review | Screens | SEGA | 8/10 |  |
 | Outlander Game Details | Screens | Mindscape | |  |
 | Outlaw Golf Game Details | Screens | TDK | |  |
 | Outlaw Golf / Darkened Skye Game Details | Screens | Simon & Schuster | |  |
 | Overlord: Minions Game Details | Review | Screens | Codemasters | 7/10 |  |
  | Override Game Details | Screens | Data East | |  |
 | Oyaku de Asoberu DS Ehon: Ukkari Penelope Game Details | Screens | Tecmo | |  |