The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Missing GameID parameter (Infobox) (0 members)
- Missing IRD parameter (GameID) (0 members)
- Missing game mode parameter (Infobox) (732 members)
- Missing genre parameter (Infobox) (17 members)
- Missing internal resolution parameter (Infobox) (2,026 members)
- Missing release date parameter (Infobox) (108 members)
- Missing release type parameter (Infobox) (36 members)
- Mobile Suit Gundam (Series) (13 members)
- Mojang Studios (Developer) (1 member)
- Mondo Productions (Developer) (1 member)
- MonkeyPaw Games (Publisher) (2 members)
- Monkey Bar Games (Developer) (5 members)
- Monkey Island (Series) (1 member)
- Monolith Productions (Developer) (6 members)
- Monopoly (Series) (1 member)
- Monster Hunter (Series) (2 members)
- Monumental Games (Developer) (2 members)
- Moonbite Games (Developer) (1 member)
- Moonbite Games (Publisher) (1 member)
- Moonbot Studios (Developer) (1 member)
- Mortal Kombat (Series) (4 members)
- Mossmouth (Developer) (1 member)
- Mossmouth (Publisher) (1 member)
- Most Wanted Entertainment (Developer) (2 members)
- MotoGP (Series) (6 members)
- MotorStorm (Series) (4 members)
- Move Street Cricket (Series) (2 members)
- Move handler: Fake (Config) (1 member)
- Move handler: Mouse (Config) (3 members)
- Moving Player (Publisher) (2 members)
- Mugen Souls (Series) (2 members)
- Multi-platform (Release type) (1,167 members)
- Multiplayer (Game mode) (815 members)
- Multithreaded RSX: Off (Config) (2 members)
- Multithreaded RSX: On (Config) (25 members)
- Music (Genre) (83 members)
- Mutated Software (Developer) (1 member)
- Mutated Software (Publisher) (1 member)
- Muv-Luv (Series) (5 members)
- Mycom (Publisher) (1 member)
- Mynavi (Developer) (3 members)
- Mynavi (Publisher) (2 members)
- N-Space (Developer) (1 member)
- NASCAR (Series) (6 members)
- NBA (Series) (3 members)
- NBA 2K (Series) (13 members)
- NBA Live (Series) (4 members)
- NCAA Basketball (Series) (3 members)
- NCAA Football (Series) (7 members)
- NHL (Series) (10 members)