The home planet of the Valorians, a peaceful race of somewhat Elven telepathic humans, has been conquered by an evil race of lizard-, frog-, bug-, and fish-men called the Rulons. Four hundred Valorian survivors use an experimental Time Travel device to go back in time and escape, but they inadvertently drag a Rulon ship back with them. Stuck in prehistoric times, they fight each other by strapping lasers and BFGs to dinosaurs. Holy shit, that is awesome.