Fill your idle time running around small planetoids and collecting animals to fulfill contracts, that will earn you money. Money that you can spend to upgrade your speed, attack, bullet size and others.
If you can complete all the contracts for one medal, you can get bonus gems to spend on power fruits that will give you temporary boosts and abilities on your next run.
While on your adventures through miniature space be sure to watch out for the predators they will eat you in one hit! Better shoot them before they touch you.