The year is 2525. It is a time of war. As Bacterian continued to attack the planet Earth, humanity desperately turned to a new kind of alien bio-weapon to help them, the "Bydo". While the Bydo helped win the battle against Bacterian, it soon grew too intelligent and too powerful to stay under Earth's control, turning against its creators. Soon, Bacterian learned of this and convinced the Bydo to unite with them against Earth. Together, the forces of Bydo and Bacterian -- henceforth known as "Byderian" -- would destroy the universe! However, before it could come to pass, Earth used experimental weapons to blow the new unified forces out of this dimension. Unfortunately, not all was well. Somewhere, out there, Byderian continues to learn, to evolve, to plot and plan... Somewhere in the distance past of 2219... Earth is once again under siege, and it's up to a small squadron of brave pilots to stop this new threat of Byderian before they can realize their evil intentions...