There are 12 O Prefix Letter NES/Famicom/Dendy Games, available on DOS Gamer.
| © Japan Uncategorised |
| © Japan Uncategorised |
| © Japan Uncategorised |
| © Japan Uncategorised |
| ©1985 Pony Canyon, Inc. Japan Action |
| ©1991 Color Dreams, Inc. USA Action |
| ©1989 Taito America Corporation, Taito Corporation Japan Action |
| © USA Uncategorised |
| ©1986 Acclaim Entertainment, Inc., Kawada, Co. Ltd USA Strategy |
| ©1987 Victor Musical Industries, Inc. Japan Action, Role-Playing (RPG) |
| ©1991 Hot-B Co., Ltd. Europe Action |
| ©1992 Virgin Games, Inc. USA Strategy |