| Mega Twins (World 900619) | 1990 | Capcom | mtwins | Platform / Fighter Scrolling | 7.36 |
| Mercs (USA 900302) (clone of: mercs) | 1990 | Capcom | mercsur1 | | 0.00 |
| Mercs (USA 900608) (clone of: mercs) | 1990 | Capcom | mercsu | Shooter / Walking | 0.00 |
| Mercs (World 900302) | 1990 | Capcom | mercs | Shooter / Walking | 7.69 |
| Michael Jackson's Moonwalker (bootleg) (clone of: mwalk) | 1990 | bootleg | mwalkbl | Maze / Fighter | 0.00 |
| Michael Jackson's Moonwalker (Japan, FD1094/8751 317-0157) (clone of: mwalk) | 1990 | Sega | mwalkj | Maze / Fighter | 0.00 |
| Michael Jackson's Moonwalker (Mega-Tech) | 1990 | Sega | mt_mwalk | Platform / Fighter Scrolling | 7.85 |
| Michael Jackson's Moonwalker (US, FD1094/8751 317-0158) (clone of: mwalk) | 1990 | Sega | mwalku | Maze / Fighter | 0.00 |
| Michael Jackson's Moonwalker (World, FD1094/8751 317-0159) | 1990 | Sega | mwalk | Maze / Fighter | 7.98 |
| Minasanno Okagesamadesu! Daisugorokutaikai (MOM-001)(MOH-001) | 1990 | Monolith Corp. | minasan | Tabletop / Mahjong | 0.00 |
| Mini Vaders | 1990 | Taito Corporation | minivadr | Shooter / Gallery | 0.00 |
| Mizubaku Daibouken (Japan) (clone of: liquidk) | 1990 | Taito Corporation | mizubaku | Platform / Fighter Scrolling | 0.00 |
| Monky Elf (Korean bootleg of Avenging Spirit) (clone of: avspirit) | 1990 | bootleg | monkelf | | 0.00 |
| Mosaic | 1990 | Space | mosaic | Puzzle / Drop | 5.83 |
| Mosaic (Fuuki) (clone of: mosaic) | 1990 | Space (Fuuki license) | mosaica | Puzzle / Drop | 0.00 |
| Mundial 90 | 1990 | Inder | mundial | | 0.00 |
| NAM-1975 (NGM-001)(NGH-001) | 1990 | SNK | nam1975 | Shooter / 3rd Person | 7.25 |
| Nemo (Japan 901120) (clone of: nemo) | 1990 | Capcom | nemoj | Platform / Fighter Scrolling | 0.00 |
| Nemo (World 901130) | 1990 | Capcom | nemo | Platform / Fighter Scrolling | 8.85 |
| Neo-Geo | 1990 | SNK | neogeo | BIOS | 6.81 |