Hop into your spaceship and fly out to the Stardust belts! The more Stardust you collect the more powerful space rockets you can purchase, and if you bet some of the Stardust you have already earned you can quickly multiply your profit!
But beware of rogue asteroids and alien creatures. The treacherous Vitruvians are cruising around out in the belts as well, not to mention the mysterious Bwlorgs.
No micro-transactions or IAP. Pay once and get the whole game!