A research installation developing the next-generation of Metal Slugs is attached by unknown forces and a disc containing Metal Slug secrets has been stolen. Lead Marco, Tarma, Eri and Fio into "The Corridor of Fire" to recover the secrets and destroy the paramilitary syndicate known as the Ptolemaic Army.
Five massive stages and all new enemies
Take up arms against this ultimate weapon of destruction "The Doomsday Machine" that fuses the mysterious power of ancient ruins with that of Metal Slug science
Wage an assault on the enemy's underwater stronghold.
Find a factory producing robotic weapons developed from the Government Army's data for next-generation Metal Slugs.