Atlus U.S.A. today announced that gamers everywhere should get ready for Metal Slug XX for the PSP (Playstation Portable) system at the bargain price of $19.99. Metal Slug is an over-the-top, run-and-gun shooter full of explosions, weapons, and mechanized machines to ride. The cartoon mayhem has kept hardcore and casual gamers entertained for over a decade. Relive the glory and charm of old schoo... more.