Excellent little game and very polished. Nice graphics and sound choices. The voice instructions are excellent way to explain the controls. The movement speed and inertia are nicely balanced.
Only suggestions are I didn't get any sense of time pressure, maybe if you don't get to the planets in time they could get destroyed? Other ideas are a trade off between power to shields v guns v thrusters much like the old X-wing Star Wars games.
I really had fun flying around though, great work!