Here on the planet Colura lived two different tribes. One was the Petras, a highly civilized tribe. Another was the Basrah, a vicious tribe. The larger Basrah all of a sudden declared war on the Petras. The Petras were very civilized, and were pacifists who did not possess enough arms and weapons to protect themselves against the Basrah's attack. They were quickly driven underground without much resistance. A handful of the Petras were left and a few ex-captives who barely escaped from the Basrah were waiting to be rescued. Finally the Petras developed a mini-size rescue bike which they called Gilgitt Petras. They blasted off on Gilgitt Petras from their secret hideout to rescue the Petras who still remained behind.
Race your bike along thrilling backgrouns as you battle alien enemies. The serenity of the space city is broken as players blast off into space from the gate in order to save their people who are left in the battlefield.
--From the NES Seicross instruction manual.