| Id | Name | Systems | Actions |
|---|---|---|---|
| 3255 | Nova the Squirrel | NES | |
| 4098 | Nuclear Throne | Linux | |
| 560 | Nuts & Milk | NES | |
| 1820 | Nuts & Milk | MSX | |
| 530 | Oddworld Adventures | GB | |
| 1577 | Oddworld Adventures II | GBC | |
| 1568 | Oddworld: Abe's Exoddus | PSX | |
| 783 | Oddworld: Abe's Oddysee | PSX | |
| 1581 | Oddworld: Munch's Oddysee | GBA | |
| 3220 | Oekaki Logic | SNES | |
| 3686 | Office Yeo In Cheon Ha | Arcade | |
| 1752 | Oil's Well | Coleco | |
| 3751 | Oil's Well | C64 | |
| 2136 | Old Tower | ZXS | |
| 1309 | Olympic Gold: Barcelona '92 | Genesis | |
| 3550 | Olympic Summer Games | Genesis | |
| 4198 | Omega Race | C64 | |
| 3611 | Omicron | C64 | |
| 1094 | On the Ball | SNES | |
| 4207 | One Button Vania | Flash | |
| 2738 | One Chance | Flash | |
| 3168 | One On One | PSX | |
| 1914 | One Piece Mansion | PSX | |
| 329 | Operation C | GB | |
| 692 | Operation Logic Bomb | SNES |