Great port. "Galaga" would be great on the Mega Drive too, by the way. Unfortunately, there’s no official release for it, on that console. Or "Galaga '88", that would be really awesome on MD. There are good ports of this game for the Game-Gear and the PC-Engine called "Galaga '90", sadly no MD version exists so far, but having that game on the Mega-Drive would be fantastic, too.