The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- 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) (1,165 members)
- Multiplayer (Game mode) (814 members)
- Multithreaded RSX: Off (Config) (2 members)
- Multithreaded RSX: On (Config) (24 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)
- NHL 2K (Series) (4 members)
- NIS America (Publisher) (2 members)
- NOW Production (Developer) (3 members)
- Naked Sky Entertainment (Developer) (2 members)
- Namco Tales Studio (Developer) (4 members)
- Naruto: Ultimate Ninja (Series) (5 members)
- National Geographic Games (Publisher) (1 member)
- Natsume-Atari (Developer) (2 members)
- Natsume (Publisher) (2 members)
- NaturalMotion (Developer) (2 members)
- Naughty Bear (Series) (1 member)
- Naughty Dog (Developer) (5 members)
- Navel (Developer) (1 member)
- Need for Speed (Series) (9 members)
- Neko Entertainment (Developer) (2 members)
- Nerve Software (Developer) (1 member)
- NetherRealm Studios (Developer) (4 members)
- Netplay tested (Netplay) (581 members)
- Network status: Connected (Config) (9 members)
- Network status: Disconnected (Config) (1 member)
- Neutron Games (Developer) (1 member)
- Neverland (Developer) (2 members)
- Neversoft (Developer) (9 members)
- New 38th Floor Productions (Publisher) (2 members)
- News (Genre) (1 member)
- Nex Entertainment (Developer) (3 members)
- Next Level Games (Developer) (1 member)
- Nihilistic Software (Developer) (3 members)
- Nihon Falcom (Developer) (2 members)
- Nihon Falcom (Publisher) (2 members)
- NinjaBee (Developer) (1 member)
- Ninja Gaiden (Series) (5 members)
- Ninja Theory (Developer) (3 members)
- Nippon Ichi Software (Developer) (11 members)
- Nippon Ichi Software (Publisher) (37 members)
- Nitroplus (Developer) (2 members)
- Nitroplus (Publisher) (1 member)
- Nobilis (Publisher) (1 member)
- Noego (Developer) (1 member)
- North America (Release region) (1,616 members)
- Novarama (Developer) (1 member)
- Now Production (Developer) (1 member)
- Number None (Developer) (1 member)
- Number None (Publisher) (1 member)
- O-Games (Publisher) (2 members)
- OG International (Publisher) (1 member)
- O Games (Publisher) (1 member)
- Obsidian Entertainment (Developer) (4 members)
- Obut Pétanque (Series) (2 members)
- Oddworld (Series) (3 members)
- Oddworld Inhabitants (Publisher) (3 members)
- Old School Games (Developer) (2 members)
- Omega Force (Developer) (33 members)
- Omni Systems (Developer) (1 member)
- One Piece (Series) (4 members)
- One True Game Studios (Developer) (1 member)
- Ongakukan (Developer) (2 members)
- Ongakukan (Publisher) (2 members)
- Operation Flashpoint (Series) (2 members)