Too much magic if you are creating a new system! Cool for it to be out of space, however, make different species. Each player can introduce their own species to the game and they have to come up with their own abilities. For example, I could come up with a species called the Crysatlintists. They could be humanoid in stature, but basically look like humans covered in a think layer of crystal. Then I would come up with abilities for the species.
So, maybe this species lives deep inside of their planet and, due to their diamond like skin, they can withstand great pressure. However, they probably weight about twice as much more than their average human counter-part and may be slower. Being made of such material they can redirect light in the area and reform various parts of their body.
If someone's species ends up being too strong or to ridiculous, the group could take a vote and make slight changes. When the changes are done the character's race becomes canon and anyone can use them henceforth.