The year is 1990. Low in the night sky appears an alien moon from which waves of ships descend upon Europe. Their occupants establish a new country called Greater Leutonia. The evil Leutonians, led by Colonel Krag, set out to conquer the world. In the wee hours of the morning the Leutonians land a zeppelin in Washington DC and kidnap Dr. Barnstorff and his beautiful daughter, Jane.
It's all up to you, a young American scientist, and your newly perfected rocket powered flying suit. Only you, by becoming Rocket Ranger, can rescue the Barnstorffs and save the world from the oppressive rule of the Leutonians. Go to it!
--From the NES Rocket Ranger instruction manual.