I really enjoyed this, played all the way through until I'd completed the campaign. I think the music levels are a bit low compared to the canon sound. The AI was hard to figure out, and the random nature of the upgrades offered made it hard to build a ship in the way you want. This turned out to be a good thing though because it forced me to play to my ship's strengths, rather than build the ship to match the way I wanted to play. I ended up with a lot of top speed and canon range, which meant I adopted a sort of hit-and-run approach where I had to keep my distance from the enemy. If I had access to all the upgrades, I think I would have naturally tried to improve my turning circle to out manoeuvre the AI.
I'm not sure if the mouse clicks are necessary, maybe you could have had the ship just follow the mouse constantly? I might have preferred wasd ultimately though.