This is the backstory of the Xevious series:
Chapter 1: The Rise of the GAMPEdit
A hundred millennium (100,000 years) ago, humankind was capable of producing amazing technologies. Chief among those was the Genetic Artificial Matrix Producer, a bio-computer which mass-produced "inferior humans" - clones. These clones (nicknamed GAMPs after the machine) were considered expendable material. Bred to have enhanced strength and require little food or sleep, they were used for menial labor, hazardous details and sometimes, bodyguards and companions for humans. As the time passed, the programmed genetic blueprinting of the GAMPs began to corrupt.
This corruption caused startling results. Bred to be compliant and servile, the GAMPs began to develop their own sense of will, thoughts and ideas. However, the GAMP's simple brains were not designed to handle these complex thoughts, and as a result became unstable.
Although originally programmed to be servants to humans, the corrupted GAMPs re-interpreted the program. To GAMPs, humanity was imperfect and needed protection. Therefore, the best way to protect humanity was to place it under the control of superior beings. The GAMPs seized control of the humans, eradicating those "threats" who stood in their way.
However, nature always has the last word in history. As the Earth entered its ice age, the GAMPs, following their programming, planned a relocation of the humans under their "protection." Six class M planets were discovered, viable relocation points for the human race: Terminus, Atlantus, Daerius, Krakatos, Bagurius and Xevious.
The humans were gathered by their GAMP "protectors." They were stored in hyper-sleep for the thousand-year starship journey. One by one the ships were launched and headed into hyper-space. However, the final group of humans, bound for Bagurius, rebelled against their GAMP masters. In a bitter rebellion, the humans and GAMP clashed. The GAMPs were destroyed, leaving the Bagurius contingent on Earth.
Chapter 2: XeviousEdit
Four thousand years later, the ice age receded and humans had another chance to prosper on Earth. However, that prosperity did not last long. Volcanic eruptions jarred the Earth's crust and melted the ice caps, destroyed what little was left of Earth's once great civilizations. Many abandoned underground GAMP bases were unearthed in the eruptions, one of which contained a small starship.
A desperate attempt to survive the cataclysmic upheavals was quickly put into action. Mu, a brave pilot and Eve, his android assistant, were sent on a mission to Xevious (the nearest of the 6 planets), hoping to make contact with their human ancestors.
However, as Mu discovered as he disembarked to explore Xevious, the planet was overrun with GAMPs. The GAMP had evolved further, this time developing extra sensory powers. Mu was detected and imprisoned. He shared his cell with Mio, an Xevian dissendenrt. Mio told Mu of the GAMP's plan to return Earth to their "protection." Their plan was to first activate SOL, an advanced version of the Genetic Artifical Matrix Producer. SOL would create advanced GAMP that would re-seize control of the planet. Then the Xevious GAMPs would return to Earth.
Mu pleaded with his GAMP captors to withdraw their plans. When they denied his requests, Mu and Mio planned their escape. They manged to get as far as the prison walls, but the GAMP were on the verge of overwhelming them. They were rescued by the timely intervention of Eve, who had evaded the GAMPs' ESP detection. The three began their long hyper-space trek back to Earth, armed with an extensive knowledge of the GAMPs and their plans.
Chapter 3: SolvalouEdit
Back on Earth, thousands of years had passed. Humans had risen up into an advanced civilization. Most of them failed to realize the awful doom that awaited them. All except two research scientists: Susan Meyer and Akira Sayaka. Meyer, Sayaka and their team had discovered and excavated a gigantic tower buried in the Nazca plateau of Peru. The tower by their estimation, was over ten thousand years old and yet the most technically advanced object on Earth! This tower was SOL, the replication unit the GAMP left behind on Earth.
One day, as the team strove to understand the ancient machine, it awoke. In a furious outpouring, the GAMPs had returned to Earth! GAMP UFOs clouded over the South American skies and the humans were helpless to stop them. The GAMPs soon spread across the land, taking back what had once been theirs. Things looked hopeless, yet again, for humanity.
Suddenly, hyper-space tore apart as a lone ship strekef across Earth's skies! It was Mu, Mio, and Eve! With the information they brought from Xevious, they modified heir ship, rechristened the Solvalou, to combat the GAMP forces and their ESP powers. After ten thousand years under GAMP rule, the humans finally have a chance to defeat the GAMP! The battle begins...