I think Galaga has more variety than Galaxian. The way the aliens move into formation, tractor beams, double shooters, challenge stages, more variety of enemies and varying levels of dificulty throughout the game e.g. gets easy again at pattern 10 - aliens don't shoot during formation. Galaxian is probably more repetitive and just keeps getting harder. I love both of these games and own a Galaxian cocktail cabinet but we don't play it all that often anymore, I've noticed a guy on Ebay selling 3 in 1 PCB's, one has Space Invaders, Galaxian and Galaga, I wouldn't mind that one but by the time I get it to Australia it'll cost me close to $480 Australian.