[citation needed] It was later ported to Microsoft Xbox and PlayStation 2 as a stand-alone game, and along with Metal Slug 4 as a compilation in North America and South Korea.
Players can choose from four playable characters: Marco, Tarma, Eri, or Fio, each tasked with completing five missions while battling numerous enemies.
Marco and Tarma of the Peregrine Falcon Strike Force follow in hot pursuit against the group and in the process are joined by Eri and Fio of SPARROWS.
Together once more, the quartet investigate the shrouded objective of the Ptolemaic Army, who over time grows more powerful as they are joined by a mysterious masked man and his followers.
At the end of the game, the Ptolemaic Army summons a giant demon as the final boss, which after a long battle is forced to leave Earth thanks to the heroes.