Nemesis II for Game Boy was released on August 9, 1991 in Japan. It was then re-released as a Nintendo Power edition on March 1, 2000.
Export releases :
[US] "Gradius - The Interstellar Assault [Model DMG-NE-USA]
[ES] "Nemesis II - The Return of the Hero [Model DMG-NE-ESP]
[EU] "Nemesis II - The Return of the Hero [Model DMG-NE-NOE]