Famicom Disk System version
The NES version of the game is a re-release. The game was originally made for the Famicom Disk System, an add-on for the NES that allowed players to use special floppy disks to save and load entire games. This version also had slightly different music which used the add-on's extra sound channels.
References to the game
Upa, the main character of this game, was also featured in the Parodius
series as a playable ship, and in Wai Wai World 2: SOS!! Paseri Jou
(Wai Wai World 2: SOS from Parsley Castle), a Japanese-only all-stars game made by Konami for the Famicom in the early 1990s.