| Map | Title | Author | Players | |
|---|---|---|---|---|
| ONS-Maelstrom | Maelstrom | 10-32 | ||
| ONS-Maelstrom-NV | Maelstrom: No Vehicles | 8-32 | ||
| ONS-MagicIsle-V8-Solace | MagicIsle-)o( | 16-32 | ||
| ONS-magma | Magma The First Arena | 14-24 | ||
| ons-Magma1 | Magma | Unknown | ||
| ONS-Majestic | Majestic | 12-24 | ||
| ONS-Majestic-ECE | Majestic | 12-24 | ||
| ONS-MantaWars_Of_Alaros | Manta Wars of Alaros | 8-12 | ||
| ONS-MarioIsland | Mario Island | 14-20 | ||
| ONS-MarioLand | Mario World | 4-8 | ||
| ONS-mars3 | Battle for Mars | 12 | ||
| ONS-MassDestruction | MassDestruction | 8-16 | ||
| ONS-MassDestruction-[ECE] | Mass Destruction | 16-32 | ||
| ONS-MasterBath-RMD-sentinelbeta | ONS-MasterBath-RMD-sentinel | 8-32 | ||
| ONS-MasterBathv2 | ONS-MasterBathv2 | 10-16 | ||
| ONS-MasterShower-V3-SP3 | Master Shower | 16-32 | ||
| ONS-MaxFrostmurii | MaxFrostMuri | 12-32 | ||
| ONS-MBB-Storage Facility_SE | ONS-MBB-Storage Facility_SE | 12 | ||
| ONS-MBB-Weapon_Outpost_V3 | Weapon Outpost | 8-20 | ||
| ONS-MechaTorlan | MechaTorlan | 8-32 | ||
| ONS-Medieval | ONS-Medieval | 10-20 | ||
| ONS-MercenaryValley | Mercenary Valley | 10-14 | ||
| ONS-Mesa's | Mesas | 16-24 | ||
| ONS-MeteorCity | Meteor City | Unknown | ||
| ONS-Meteorite | ONS-Meteorite | Unknown | ||
| ONS-Midget&Sole | ONS-Midget&Sole | 1-2 | ||
| ONS-Midworld | Midworld | 10-14 | ||
| ONS-Minus-ECE | ONS-Minus-ECE | 12-32 | ||
| ONS-MoonBaseALPHA | Moon Base | 20 | ||
| ONS-MoonDragon | MoonDragon | 10-18 | ||
| ONS-MoonLight | Moonlight | 10-16 | ||
| ONS-Mothership | Mothership | 24-32 | ||
| ONS-MothershipFixed | Mothership | 24-32 | ||
| ONS-MothershipFIXXORD | Mothership | 24-32 | ||
| ONS-MothershipFIXXORD | Mothership | 24-32 | ||
| ONS-MPC-Basement-Home-Theater-BadWolf-RC1 | ONS-MPC-BASEMENT-HOME-THEATER | 24-32 | ||
| ONS-MudSling | MudSling | 12 | ||
| ONS-MudSling][ | MudSling][ | 12 | ||
| ONS-MZ-ViperLake | Viper Lake | 8-12 |