Some suggestions. Score should be scale with difficulty. Total score should be sum of highest scores for each map. The current total score is simply a sum of score you ever took (the more you play, the more score you got), which is not an accurate reflection of playing skill. Because the score is original an exp, developer may need to rethink what the "score" represent.
About Uranium to Stars conversion, how about making Reactor an option to do such work? As developer said, "Uranium is too easy to get" (if you know how :) ), for some _rich_ player, the Reactor is primary a safe, resources to Uranium conversion is redundant. If it is possible, the stars conversion rate should be scaled to be, like, starting from 0.6 stars per 1hr per 100K uranium (lv1), and getting faster as 'reactor' lv going up. It is about 15stars per days initially, and about 45stars per days at 'reactor' lv25. It is just equal killing 3-9 rift worms per day, but a funny addition of stars sources, I think.
 "Starship Commander"){kind=icon}
 "Nova Raider"){kind=icon}
okay, ill fix this in tonights update. ill make it so the difficulty, and time are factored in. (EDIT) fixed!