Home System is hand-coded as a tutorial level. The next step is to generate whole solar systems of random planets so that there is infinite play. I still have a few tricks hidden in the engine that aren't revealed by the tutorial, either. My hope is that the fun of the game will be a mixture of the tight reward cycle of taking shots with the loose reward cycle of exploration and discovery.
Jan 21 Update: I've implemented most of the intended features, ported and optimized for mobile (about a 10x perf increase over the jam version!), and am now preparing for a mobile release of the game. I took the original demo down from the web in anticipation of releasing the real version in the next two weeks.