I loved this, super satisfying! IIRC there is a bug with get_vector() with thumbstick inputs and it’s better to get_axis() because it can have some drift, and in this case the shots generally fire a little askew. Had so much fun I just played that way, then a second time remapping to d-pad for no drift. I think my only issue is I couldn’t pause and recofigure the controls.
As others noted, growing the base really took a back seat, it would have been cool if destroyed bases left more materials than asteroids, or something similar, but even as-is, this was a real treat.