Obliterator ![[Language: English]](english.gif) ![[Media: Disc]](disc.gif) | 1989 | Melbourne House |
| Ocp Advanced Art Studio | 1985 | Rainbird |
Official Father Christmas (The) ![[Media: Cassette]](cass.gif) | 1989 | Alternative Software Ltd. |
| Oh Mummy | 1984 | Amsoft |
| Oh Mummy | 1984 | Amsoft |
Ole Toro ![[Language: Spanish]](spanish.gif) | 1985 | Dinamic Software |
| Olli & Lissa - The Ghost Of Shilmore Castle | 1987 | Firebird |
| Olli & Lissa 3 - Candlelight Adventure | 1989 | Codemasters |
| One Man And His Droid | 1985 | Mastertronic |
| Operation Gunship | 198? | Codemasters |
| Operation Gunship | 1989 | Codemasters |
| Operation Hanoi | 1990 | Players Premier |
| Operation Hormuz | 1987 | Alternative Software Ltd |
| Operation Thunderbolt | 1990 | Ocean |
| Outrun (Audio Sound Track) | | U.S. Gold |
| Overlander | 1988 | M.C.M. Software |