| Marilunker | Tsurumidou | Spelunker | Action > Platformer | NES | G, T | Improvement | 1.0 | 01 Jan 1999 |
| Marble City | TLT | Battle City | Action | NES | G, S, L, T, GP, O | Complete | 3.74 | 25 Dec 2010 |
| Mappy Patrick St.'s Day Edition | Жукороп | Mappy | Action > Platformer | NES | G | Complete | 1.0 | 16 Mar 2021 |
| Mappy Graphics Patch | NoPhoneBlemo | Mappy | Action > Platformer | NES | G, O | Improvement | 1.0 | 05 Dec 2021 |
| Mappy 30th Anniversary Edition | Makimura Manufacturing | Mappy | Action > Platformer | NES | S, O | Improvement | 1.0 | 28 Oct 2015 |
| Map Mishap | Leet Sketcher | Final Fantasy III | Role Playing | SNES | G, L | Bug Fix | 1.8 | 30 Sep 2017 |
| Mansion of Insmouse: Mario Madness Edition | Benjamin Stevens | Innsmouth no Yakata | Action > Shooter | VB | G, L | Complete | 1.0 | 10 Dec 2012 |
| Maniac Strikers + Zero Boss Hack | [John] | The King of Fighters 2000 | Action > Fighting | PS2 | GP, O | Improvement | 1.0 | 16 Mar 2019 |
| Maniac Mansion Uncensored | gzip | Maniac Mansion | Adventure | NES | G, T | Improvement | 1.0 | 24 Nov 2020 |
| Maniac Mansion MMC5 Patch | Dracula X | Maniac Mansion | Adventure | NES | O | Improvement | 1.0 | 26 Nov 2020 |
| Manall's Waluigi RPG | Manall Lockhart | Super Mario RPG: Legend of the Seven Stars | Role Playing | SNES | G, L, T, GP, O | Complete | 1.0 | 10 May 2022 |
| Manall's FF1 | Manall Lockhart | Final Fantasy | Role Playing | NES | G, L, T, GP | Complete | 2.2 | 28 Apr 2022 |
| Makaitoushi Sa-Ga Title Patch | Killa B | Final Fantasy Legend | Role Playing | GB | G | Improvement | 1.0 | 14 Apr 2007 |
| Makaimura Arcade Conversion - Fair Play | lancuster | Ghosts 'n Goblins | Action > Platformer | NES | L, T, GP, O | Addendum | 1.0 | 09 Dec 2016 |
| Makaimura Arcade Conversion | 2CH | Ghosts 'n Goblins | Action > Platformer | NES | G | Improvement | 1.0 | 01 Jan 2010 |
| Makai Island Restoration | SCD | Makai Island | Action Adventure | NES | G, T, GP | Improvement | Final | 24 Oct 2019 |
| Majou Densetsu II: Daimashikyou Galious SRAM save patch | RGBA_CRT | Majou Densetsu II: Daimashikyou Galious | Role Playing > Action RPG | NES | O | Improvement | 1.0 | 26 Mar 2018 |
| Majora's Mask Redux | Maroc | The Legend of Zelda: Majora's Mask | Action Adventure | N64 | GP | Improvement | 2.0 | 24 Nov 2020 |
| Major Fixes for E.V.O.: Search for Eden | SCD | E.V.O.: Search for Eden | Role Playing > Action RPG | SNES | G, T, GP | Improvement | Final | 16 Jul 2017 |
| Main Script F2 Fix | abw | Dragon Warrior II | Role Playing | NES | O | Improvement | 1.0 | 20 Oct 2019 |
