All Games
 |
 Game Title | Year | Publisher | Genre |
| Olympic Spectacular | 1987 | Alternative Software Ltd. | Action, Sports |
| Omega | 1989 | ORIGIN Systems, Inc. | Strategy |
| Omega Race | 1982 | Commodore, Handic software AB | Action |
| Omni-Play Basketball | 1989 | Mindscape, Inc. | Sports |
| Omni-Play Horse Racing | 1986 | Mastertronic Group Ltd. | Simulation, Sports |
| On-Court Tennis | 1984 | Activision (UK) Limited | Sports |
| One Man and His Droid | 1985 | Mastertronic Group Ltd. | Action |
| On the Tiles | 1987 | Firebird Software Ltd. | Action |
| Oo-Topos | 1986 | Polarware | Adventure |
| Operation Market Garden: Drive on Arnhem, September 1944 | 1985 | Strategic Simulations, Inc. | Simulation, Strategy |
| Operation Thunderbolt | 1990 | Ocean Software Ltd. | Action |
| Operation Wolf | 1988 | Ocean Software Ltd., Taito America Corporation | Action |
| O'Riley's Mine | 1983 | Datasoft, Inc. | Action |
| The Ormus Saga II: Guild of Death | 1993 | CP Verlag | Role-Playing (RPG) |
| Oubliette | 1983 | Bear Systems | Adventure, Role-Playing (RPG) |
| Outlaws | 1985 | Ultimate - Play the Game | Action |
| OutRun | 1988 | U.S. Gold Ltd. | Racing / Driving |
| OutRun Europa | 1991 | SEGA Corporation, U.S. Gold Ltd. | Racing / Driving |
| Overlander | 1988 | Elite Systems Ltd. | Action, Racing / Driving |
| Overlord | 1990 | Virgin Mastertronic Ltd. | Strategy |
| Over the Net | 1991 | Genias | Action, Sports |
| Over the Top | 1987 | Systems Editoriale s.r.l. | Sports |
| Ozzy Versus the Universe - Part I: Demons of Topaz | 1984 | Firebird Software Ltd. | Action |
| P1x3l-pushr | 2008 | | Strategy |
| P-47 Thunderbolt: The Freedom Fighter | 1990 | Firebird Software Ltd. | Action |
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