From the Game's Introduction:
Far above the planet Clymexia, a Behemoth class starship slides through the chronoluminiferous ether. The fabric of space and time distort around it, a miracle of technology, possessed by few, and understood by fewer still. Inside, a man paces, bothered by an unidentifiable something. In a previous century, they might have called it "conscience," but for Herr Grodz, "conscience" was an unfamiliar word. He was a cyborg, created to carry out the will of the Galactic Grand Emperor, and no force in this universe or any other, could stop him from doing his duty.
The planet of Clymexia was a peaceful world. Its people were primarily farmers and simple craftsmen. They obeyed the law, paid their taxes, and saluted the Emperor. Unfortunately for them, that wasn't enough. His Most High Celestial Eminence demanded absolute loyalty, and when the citizens of Clymexia refused to be relocated to another sector to make way for the Transdimensional Conduit, they ceased to have any value to the Empire. Herr Grodz would do his duty. He would eliminate them.
Dynamos deep within the bowels of the ship whirred to life. Driven by a fusion reaction, they would generate the massive amounts of electrical power necessary to activate the Oblititron. The citizens of Clymexia had precisely six minutes to live.
Time passes; T-minus 3:00. The generators thrum with an ominous power. More time passes; T-minus 1:30. Herr Grodz's aural filter kicks in, protecting him from the deafening noise coming from the ship's reactors. The sensor's tiny alarm was lost under the shrieking wail of the charging Oblititron, but its blinking red light was not. Some object, within one AU, was generating a chronetheric field. That could mean only one thing: company.
At that moment, T-minus 0:45, the Behemoth class starship shook and rattled. It didn't feel like a collision. It felt more like the ship's walls were collapsing from within. Herr Grodz spun around, and was stopped cold in his tracks. Somehow, the intruders have managed to materialize their ship in the middle of his bridge. With one well-aimed shot from his lazon pistol, the be-Stetsoned creature blasted the main control panel to smithereens. Then, with a tip of his hat, he stepped back into his improbably placed ship and vanished for parts unknown.
Deprived of control protocols, the Oblititron's dynamos took on a new sound. It was a sound all aboard recognized from their training. The generators have entered overload...
Meanwhile, the grateful citizens of Clymexia waited to welcome their savior, but for Duke Starseed, the deed was thanks enough.
Welcome to the world of Mutant Space Cowboys, where saving planets is all in a day's work. Within these pages, you'll not only find rules to create your own Mutant Space Cowboy, but also spaceships, time travel devices, weapons, sidekicks, and enemies. So strap yourself in, and get ready to defend the underdog from the forces of greed, tyranny, and injustice.