The game was first ported to the
Family Computer in 1988 and was never released outside Japan. Presumably this was due to the fact that the Famicom version employed a custom memory mapper dubbed the VRC4, which enhanced some of the game's graphics, such as animation, thus converting the game to a standard memory mapper (as Konami later did with ''
Castlevania III: Dracula's Curse) would have been too time-consuming (since the original Gradius'' was not as popular overseas as it was in Japan). A
PC Engine Super CD-ROM² port was later released only in Japan in 1992. The graphics remained nearly unaltered, the
background music is mostly the arcade version's soundtrack in redbook audio format, and one additional stage was added that is similar to the temple stage in the NES version of
Life Force and the first stage of
Gradius III.
Gradius II was later re-released in the Japanese exclusive
Gradius Deluxe Pack for the
PlayStation,
Sega Saturn and
Microsoft Windows in 1996, and for the first time a worldwide release on the
Gradius Collection for the
PlayStation Portable in 2006. There was also a release for Mobile phones on 2004 and Windows Phone on 2010. No version of
Gradius II saw a release in
North America until its inclusion in the
Gradius Collection in
2006. The Famicom and PC Engine ports were re-released for the
Wii Virtual Console in 2007, the latter getting an international release.
Hamster Corporation released the game as part of their
Arcade Archives series for the
PlayStation 4 in 2016 and
Nintendo Switch in 2020; this was included in Konami's own
Arcade Classics Anniversary Collection for the Nintendo Switch, PlayStation 4,
Windows and
Xbox One. Multiple versions of the game were included in the 2025
Gradius Origins compilation. ==Reception==