Took some time to grok what's happening. It's a rough prototype but I feel there's a great idea in there.
The main problem is that movement is not intuitive. It's hard to predict where things will end at the next turn because they slide along the squares of different size. On top of that they shift to the other side when pushed out of screen.
I think you should try to make another prototype with the same premise but ditch the tiled/tetris representation and use actual orbits and full 360 degrees view from planets when scanning for constellations (instead of only 4 direction). Something like that could be worth exploring and it's not that hard to implement.