From the game's website
Astraterra is an adventure role-playing game set in an amazing post-apocalyptic science fantasy world. The world of Astraterra is built on the remains of a great ringworld that once revolved around the sun. After the cataclysmic events of distant past, the civilization was rebuilt and now the civilized people of Astraterra have re-discovered steam power and electricity. Besides these new wonders of technology and science, some ancient and magic-like tech-treasures still exist. Many of them are valued heirlooms or treasures found in the old ruins of the Ancestors. One example of the tech-treasures are the teleports, which can be used for instantaneous travel anywhere in Astraterra. The teleports have been silent for a millenia, and just recently a way to restart them was discovered. But there is a problem: as the ringworld broke into pieces and the teleports lost their connection to one another, there is no way of knowing what lies on the other side of a teleportal. Most of the teleports are still inactive and bold explorers are needed to activate them again and connect them with all the other re-activated teleports. Conveniently, the player characters happen to be bold and adventurous enough to become teleport explorers.