| # | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v | w | x | y | z |
| Game Title | Platform | Date Added |
|---|---|---|
| Oddworld: Abe's Exoddus | PC | 02/25/2003 |
| Oddworld: Abe's Oddysee | PC | 02/25/2003 |
| Oddworld: Munch's Oddysee | Xbox | 11/30/2004 |
| Okami | PlayStation 2 | 09/24/2006 |
| Oni | PlayStation 2 | 03/05/2003 |
| Operation Flashpoint: Cold War Crisis | PC | 02/25/2003 |
| Outlaw Golf | GameCube | 08/01/2003 |
| Outlaw Volleyball | Xbox | 07/24/2003 |
| Outlaw Volleyball Remixed | PlayStation 2 | 10/08/2006 |