World 3 is the fourth world unlocked. You gain access to it after you beat all normal stages in World 2. It has a purple background.
Unlocking the normal and boss levels is the same as in Worlds 1 & 2.
Note: Boss levels will be unlocked after you beat all normal stages, like in previous worlds.
The highest difficulty level found in this world is Expert.
Rewards & Unlocks
Area 1: 2 Radar
Area 2:10 Medals
Area 3: 1 Mobile Satellite
Area 4: 10 Medals
Area 5: 1 Ap Level Max
Area 6:10 Medals
Area 7: 3 Rewards Up
Area 8: 10 Medals
Area 9: 1 Ap Level Max
Area 10: 10 Medals
Area 11: Ap Level Max
Area Final: 100 Medals
- -By Unlocking POW's
Area Final: Trevor Mummy
Boss Area 1: Elite Arabian Soldier
Boss Area 2: Cyborg Allen'O Neil
Boss Area 3:Morden Robot
Boss Area 4: Mars People Cadre
- All Metal Slug characters in World 3 are zombie versions of the originals
- The Enemy AI in World 3 will now use unit specials more frequently than in World 3.
- This is the only normal world to have more than 7 prisoners per level.