The player controls an insect-sized warrior named "Kai", who takes on a vast army of cyborg insects to free the insect world from the dark ruler queen. The game uses two buttons: an upgrade-able main shot and a seemingly random selection of secondary weapons.

Originally there was a conversion to the Famicom with minor changes, as well as a revised version for the Sega Mega Drive. The original arcade version is also in Taito Legends 2.

The Sega Mega Drive version has a number of differences: "realistic" sprite work (compared to the "cute" style of the original), brand new music, a reworking of the secondary weapon system and the removal of the autofire powerup, and new stage sections, among other things. While the developer is unclear, it could be either Taito or Hot-B; otherwise it was published in Japan by Hot-B and in the United States by Sage's Creation.