The game follows the same formula as its predecessors, with players taking control of either Marco, Tarma, Eri, or Fio as they battle their way through hordes of enemies to reach the end of each level. The gameplay involves running, jumping, and shooting, with an emphasis on strategy and quick reflexes. The game features a variety of new and improved weapons, including the trusty "Slufguns" and the more powerful " Big Shot".

Metal Slug X was not released as a standalone PlayStation 2 game, it is widely available on the platform as a key title within the Metal Slug Anthology