I'm glad I came back and spent some more time on this one. This seems like it could be the seed of something really interesting. Here are the thoughts I had while playing:
The controls were frustrating enough, especially when piloting a fleet with ships of different speeds, that I wondered how this would be with no controls at all, as more of an idle-game experience. Or maybe with more generic controls like "stay near this point and defend" or "go over here and mine."
The laser graphics scaling were really wonky with higher power lasers, and destroying rocks that were completely off-screen wasn't great. On the same topic, waiting 10 seconds for rocks to wander onto the screen wasn't fun.
I think that the bending of the game towards the jam theme may have actually harmed gameplay a bit.
The music didn't really seem to fit.