A PDF of the Japanese manual can be downloaded at Video Game Den (under "OMAKE").
A PDF of the American manual can be downloaded at The NES Files.
page 2, "Object of the game"
You are a Galactic Commando deep in enemy territory. Power hungry leaders of the repressive Bungeling Empire have stolen a fortune in gold from the people by means of excessive fast food taxes. Your task? To infiltrate each of thet 50 different tereasury rooms, evade the deadly Bungeling guards, and recover every stack of Bungeling booty!
A basic promotional site for the Game Boy Advance compilation. It does have some nostalgic remarks about the game from Takahashi Meijin, though.