Metal Slug XX PSP | USA | Action | 2010 | 190 MB After General Morden is defeated and captured, a mysterious army arrives from the future to save him. They reveal themselves to be the Mars People and their goal is to provide their future leader with special advanced weaponry to take on his enemies in the present. Classic Metal Slug characters Marco, Tarma, Fio, Eri, Ralf, and Clark return once again to take on General Morden and his new and improved Rebel Army.