Gulkave

Gulkave is an SG-1000 shoot 'em up game developed by Compile and published by Sega in 1986. It is a horizontal shooter, in which the player controls a spaceship that must destroy the 8 fortresses of the Gulbas Empire and several various enemies. Despite the limitations of the console, there are 30 "acts", and each "act" has a different background and there are numerous powerups available, setting it apart from most other SG-1000 shooters at the time.