Text taken from it’s official page:

We’ve ported our XCade application from Palm OS to the GP32, and are giving it away free. We’ve always been big supporters of the free software and open source movements where we can, and in that spirit want to do our small part to support this marvelous little machine.This version is running very well; it runs Space Invaders, Donkey Kong, Donkey Kong Jr., Pacman, Ms. Pacman, Pengo, Puckman and Hanglyman. Colours are broken, but otherwise runs nice. Some screen clipping is performed to fit nicely on the GP32 display without speed hit.

http://www.codejedi.com/shadowplan/gp32.html