| Mace Griffin: Bounty Hunter | Xbox | FPS / Space Sim | 6/19/2003 |
| Mad Dash Racing | Xbox | Racing/Driving | 11/15/2001 |
| Madagascar | Xbox | Action/Adventure | 5/23/2005 |
| Madden NFL 06 | Xbox | Sports | 8/8/2005 |
| Madden NFL 07 | Xbox | Sports | 8/30/2006 |
| Madden NFL 12 | Xbox | Sports | 8/30/2011 |
| Madden NFL 2002 | Xbox | Sports | 10/31/2001 |
| Madden NFL 2003 | Xbox | Sports | 8/13/2002 |
| Madden NFL 2004 | Xbox | Sports | 8/11/2003 |
| Madden NFL 2005 | Xbox | Sports | 8/9/2004 |
| Mafia | Xbox | Action/Adventure | 3/12/2004 |
| Mafioso | Xbox | Real Time Strategy | Cancelled |
| MAGATAMA | Xbox | Action/RPG | To Be Announced |
| Magic: The Gathering - Battlegrounds | Xbox | Action/RPG | 11/12/2003 |
| Major League Baseball 2K5 | Xbox | Sports | 3/1/2005 |
| Major League Baseball 2K5: World Series Edition | Xbox | Sports | 10/18/2005 |
| Major League Baseball 2K6 | Xbox | Sports | 4/3/2006 |
| Malice | Xbox | Platformer | 6/1/2004 |
| Manhunt | Xbox | Action/Stealth | 4/20/2004 |
| Marble Blast | Xbox | Family | To Be Announced |
| Marc Ecko's Getting Up: Contents Under Pressure | Xbox | Action | 2/14/2006 |
| Marvel vs. Capcom 2 | Xbox | Fighting | 3/27/2003 |
| Marvel Nemesis: Rise of the Imperfects | Xbox | Fighting | 9/20/2005 |
| Marvel: Ultimate Alliance | Xbox | Action/RPG | 10/24/2006 |
| Mashed | Xbox | Racing/Driving | Q1 2005 |
| Master Slave | Xbox | Action/RPG | To Be Announced |
| Masters of the Universe He-Man: Defender of Grayskull | Xbox | Action/Adventure | Q4 2003 |
| Mat Hoffman’s Pro BMX™ 2 | Xbox | Extreme Sports | 8/13/2002 |
| Max Payne | Xbox | Action | 12/11/2001 |
| Max Payne 2: The Fall of Max Payne | Xbox | Action/Shooter | 12/2/2003 |
| Maximum Chase | Xbox | Action | 10/28/2003 |
| MechAssault | Xbox | Action/Shooter | 11/12/2002 |
| MechAssault 2: Lone Wolf | Xbox | Action/Shooter | 12/28/2004 |
| Medal of Honor European Assault | Xbox | First Person Shooter | 6/7/2005 |
| Medal of Honor: Frontline | Xbox | First Person Shooter | 11/9/2002 |
| Medal of Honor: Rising Sun | Xbox | First Person Shooter | 11/11/2003 |
| Mega Man Anniversary Collection | Xbox | Compilations | 3/15/2005 |
| Men of Valor | Xbox | First Person Shooter | 10/19/2004 |
| Mercedes-Benz World Racing | Xbox | Racing/Driving | 3/20/2003 |
| Mercenaries | Xbox | Action/Shooter | 1/10/2005 |
| Metal Arms: Glitch in the System | Xbox | Action/Adventure | 11/18/2003 |
| Metal Dungeon | Xbox | RPG | 12/3/2002 |
| Metal Gear Solid 2: Substance | Xbox | Action/Stealth | 11/5/2002 |
| Metal Shell | Xbox | Other | Cancelled |
| Metal Slug 3 | Xbox | Action/Shooter | 5/25/2004 |
| Metal Slug 4 & 5 Bundle Pack | Xbox | Compilations | 8/16/2005 |
| Meteor Blade | Xbox | Fighting | Cancelled |
| Miami Vice | Xbox | Action | To Be Announced |
| MicroMachines | Xbox | Racing/Driving | 3/11/2003 |
| Midnight Club 3: DUB Edition | Xbox | Racing/Driving | 4/12/2005 |
| Midnight Club II | Xbox | Racing/Driving | 6/3/2003 |
| Midtown Madness 3 | Xbox | Racing/Driving | 6/17/2003 |
| MIDWAY | Xbox | Flying | Q3 2005 |
| Midway Arcade Treasures | Xbox | Compilations | 11/3/2003 |
| Midway Arcade Treasures 2 | Xbox | Compilations | 10/11/2004 |
| Midway Arcade Treasures 3 | Xbox | Compilations | 9/26/2005 |
| Mike Tyson Heavyweight Boxing | Xbox | Sports | 7/16/2002 |
| Military combat game (working title) | Xbox | First Person Shooter | Cancelled |
| Milo and the Rainbow Nasties | Xbox | Action/Adventure | To Be Announced |
| Minority Report | Xbox | Action | 11/19/2002 |
| Mission Impossible: Operation Surma | Xbox | Action/Stealth | 12/2/2003 |
| MLB SlugFest 20-03 | Xbox | Sports | 8/26/2002 |
| MLB SlugFest 20-04 | Xbox | Sports | 3/17/2003 |
| MLB SlugFest 2006 | Xbox | Sports | 6/5/2006 |
| MLB SlugFest: Loaded | Xbox | Sports | 6/15/2004 |
| Mojo! | Xbox | Puzzle | To Be Announced |
| Monopoly Party | Xbox | Family | 11/30/2002 |
| Monster 4x4 World Circuit | Xbox | Racing/Driving | Mar. 2006 |
| Monster Garage | Xbox | Racing/Driving | 11/3/2004 |
| Morrowind Game of the Year (GotY) Edition | Xbox | RPG | 10/14/2003 |
| Mortal Kombat: Armageddon | Xbox | Fighting | 10/16/2006 |
| Mortal Kombat: Deadly Alliance | Xbox | Fighting | 11/18/2002 |
| Mortal Kombat: Deception | Xbox | Fighting | 10/4/2004 |
| Mortal Kombat: Shaolin Monks | Xbox | Action/Adventure | 9/19/2005 |
| Moto-X | Xbox | Racing/Driving | To Be Announced |
| Motocross Mania 3 | Xbox | Racing/Driving | 4/26/2005 |
| MotoGP | Xbox | Racing/Driving | 5/14/2002 |
| MotoGP 2 | Xbox | Racing/Driving | 5/20/2003 |
| MotoGP 3 | Xbox | Racing/Driving | 8/30/2005 |
| Motorsiege | Xbox | Action/Shooter | To Be Announced |
| MTV Music Generator 3: This is the Remix! | Xbox | Music/Dance | 6/22/2004 |
| MTV's Celebrity Deathmatch | Xbox | Fighting | 10/14/2003 |
| MTX Mototrax | Xbox | Extreme Sports | 3/3/2004 |
| Murakumo | Xbox | Action/Shooter | 3/4/2003 |
| MVP 06 NCAA Baseball | Xbox | Sports | 1/18/2006 |
| MVP Baseball 2003 | Xbox | Sports | 3/10/2003 |
| MVP Baseball 2004 | Xbox | Sports | 3/9/2004 |
| MVP Baseball 2005 | Xbox | Sports | 2/22/2005 |
| MX 2002 | Xbox | Extreme Sports | 12/4/2001 |
| MX Superfly | Xbox | Extreme Sports | 11/21/2002 |
| MX Unleashed | Xbox | Extreme Sports | 1/12/2004 |
| MX vs. ATV Unleashed | Xbox | Extreme Sports | 3/22/2005 |
| MX World Tour: Featuring Jamie Little | Xbox | Extreme Sports | 4/6/2005 |
| Myst III: Exile | Xbox | Action/Adventure | 9/17/2002 |
| Myst IV Revelation | Xbox | Adventure | 3/28/2005 |