| Mystical Ninja 2 Starring Goemon - 4-Player coop unlocked | gallaux | Mystical Ninja 2 Starring Goemon | Action > Platformer | N64 | GP | Improvement | 1.0 | 04 Feb 2023 |
| Mystic Quest Reborn | JCE3000GT | Final Fantasy: Mystic Quest | Role Playing | SNES | G, S, L, T, GP, O | Improvement | 2.0 | 15 Jun 2012 |
| Mystic Quest Impossible Mod | JCE3000GT | Final Fantasy: Mystic Quest | Role Playing | SNES | GP | Improvement | 1.0 | 16 Aug 2011 |
| Mystic Quest EasyType | JCE3000GT | Final Fantasy: Mystic Quest | Role Playing | SNES | GP | Improvement | 1.0 BETA | 01 Sep 2009 |
| Mystic Ark EasyType | JCE3000GT | Mystic Ark | Role Playing | SNES | GP | Improvement | 1.0 FINAL | 17 Nov 2011 |
| Myon Myon | DASTARD | Son Son | Action > Platformer | NES | G, T | Improvement | 1.0 | 01 Sep 2007 |
| My Little Pony: Dr. Discord's Conquest | RetiredBrony | Mega Man 3 | Action > Platformer | NES | G, S, L, T, GP | Complete | 1.0 | 03 Jan 2014 |
| MW III Title Screen Revamp | ArcadeTV | Wonder Boy in Monster World | Action > Platformer | GEN | G | Complete | 1.2 | 16 Mar 2022 |
| Music Fix Patch | Cornholio309 | Crash Bandicoot: The Huge Adventure | Action > Platformer | GBA | S | Bug Fix | 1.0 | 03 Mar 2023 |
| Mushroom Nightmare | Shadic | Super Mario Bros. | Action > Platformer | NES | G, S, L, T | Complete | 1.5 | 02 May 2021 |
| Mushroom Kingdom Meltdown 2 | cyphermur9t | Super Mario World | Action > Platformer | SNES | G, S, L, T, GP, O | Complete | 1.0 | 07 Jan 2010 |
| Mushroom Kingdom Meltdown | cyphermur9t | Super Mario World | Action > Platformer | SNES | G, S, L, T, GP | Complete | 1.0 | 14 Jul 2009 |
| Mushroom Heaven | sinksadventure | Super Mario Bros. | Action > Platformer | NES | G, L, T, GP | Complete | 1.0 | 05 May 2022 |
| Mushroom Fever | Yakibomb | Super Mario RPG: Legend of the Seven Stars | Role Playing | SNES | L, T, GP | Complete | 1.0 | 22 Nov 2013 |
| Mush Mush - Toad and Toadette | forgotusername | Squashed | Action > Platformer | NES | G, T | Complete | 1.0 | 02 Jul 2019 |
| MUSCLE Supreme hack | DANGER X | M.U.S.C.L.E. | Action > Fighting | NES | GP | Improvement | 1.0 | 29 Jan 2016 |
| Musashi’s Sword 5 Nekketsu Samurais | DANGER X | Musashi no Ken: Tadaima Shugyou Chuu | Action > Fighting | NES | G, S, L, T, GP, O | Improvement | 1.0 | 30 Jul 2017 |
| Musashi’s Sword 4 Kendo forever | DANGER X | Musashi no Ken: Tadaima Shugyou Chuu | Action > Fighting | NES | G, L, T, GP, O | Improvement | 1.0 | 24 Sep 2016 |
| Musashi no Ken button swap | the jabu | Musashi no Ken: Tadaima Shugyou Chuu | Action > Fighting | NES | GP | Improvement | 1.0 | 01 Jan 2023 |
| Musashi no Ken 3 The Legendary Swordsman | DANGER X | Musashi no Ken: Tadaima Shugyou Chuu | Action > Fighting | NES | G, L, T, GP, O | Improvement | 3.0 | 11 Oct 2015 |
