Metal Slug XX is a side-scrolling, run-and-gun shooter released for the PlayStation Portable (PSP) in 2009. It is a part of the classic Metal Slug series, known for its fast-paced action, quirky humor, and hand-drawn, cartoonish graphics. Players battle through multiple stages filled with enemy soldiers, fantastic vehicles, and outrageous bosses while freeing prisoners of war and collecting weapon upgrades. The PSP version includes cooperative multiplayer gameplay and additional content, making it a comprehensive package for series fans and newcomers.