It was believed on Earth that the deadly BYDO Empire had been destroyed
- but now they've returned, as nasty as ever. Their ships and armies are
more powerful than before, and Earth will surely be conquered unless the
new R-90 ship can destroy them. Powered with engines that launch it into
different dimensions, and armed with the Round, Shadow and Cyclone
Forces, the R-90 has what it takes to wipe out the BYDO threat. The BYDO
mother ship must be found and destroyed to entirely erase the species
from our galaxy.