CoverMetal Slug team member Fio is missing on the cover art of the U.S. and European versions. She's on the Japanese cover art, though.
German versionIn the German PlayStation version, the blood is white by default.
VillainThe main villain is based on Saddam Hussein and his symbol is based on the swastika of the Nazis.
Information also contributed by Satoshi Kunsai and Tiago Jacques