From publisher blurb:
Rocket Age is a role-playing game that uses the Vortex System, the same system used by Doctor Who Adventures in Time and Space as well as Primeval. It is fast paced and rules-medium, modified to the setting, and meant to be played at break neck speeds in order to emulate the pulp space operas and serial movies of the 20s to today. Character creation is point based, but occupational packages can be used as templates to guide and speed up character creation. There are thirteen different species available. Starting from the inner most inhabited planets, Venus is the home to the jungle dwelling, argumentative ape-like Venusians. Earthlings are the people of Earth, and their drive and determination has spread them from Mercury to the Jovian moons, and beyond. Mars is home to, oddly enough, the Martians, but their strict caste system has caused the various castes and sub-castes to not just behave differently, but to be physically different. At the top are the royal Silthuri, though they often uneasily share power with the priestly Kastari. Warrior caste Maduri fight battles, guard their masters, and keep the lower castes in check. The Talandri craftsmen make up the most commonly seen Martian caste, whereas the merchant and diplomats of the Pilthuri the least. Then there are the hordes of the Julandri slaves, divided into the strong laborer sub-castes, and the courtesan slaves who tend to the cultural and physical needs of the ruling castes. The nomadic and savage Chanari tribes inhabit the wild deserts of Mars. Leaving Mars we come to the Jovian Moons, inhabited by the savage and degenerate Ionians, the Ganymedian wild treemen, and finally the mysterious Europans.
Wait, those planets can't support life, at least not as we know it. Right you are, except in Rocket Age they do. Just like radium fuel does not accelerate rockets to amazing speeds, and thus enables Earthlings to explore and exploit the Solar System. Instead, we are after the fun, as long as it is internally consistent. That is the design key for Rocket Age, internal consistency and damn the science. The Rule of Cool is in effect, and the setting, not to mention the system, is meant to be as cinematic as possible while maintaining a finger hold on rationality.