From the game inlay card
"It is the day after, big brother has been destroyed and the earth has to learn how to survive on its own.
You have been assigned to find the energy your planet needs to survive. The old republic stored nuclear plasma on four neighbouring planets. It is your mission to visit the twelve alien landscapes to retrieve it.
Utilising the intricate controls of your spacecraft, you leave the space station base to collect all the nuclear pods from each planet.
If you are successful, you qualify to finally collect the fusion core from the last most difficult cavern."