You're right, they had about twice the HP they should have - I found during development that once you get a few clones going, the game ended way too quickly, but I've now patched it so there are more turrets, with about half the HP. Not a perfect solution but I ran out of time before I was able to add more configurations of enemies.
Yes the player aim function was pretty bad but I had to rush to submit in time. Now that I've since slept, I was able to correct it :D If you play again, please let me know what you think. There's still a quirk with (I think) ParticleSystem stopping if you fly too close to a collider, but I've no idea how to fix that. Let me know if you do :P
The toggle, haha... I was heavily inspired by Freelancer, which (along with most of the genre) have a flight mode toggle so you can interact with UI without veering off course - but I scoped too big and ended up not having any UI interaction, so it's just a hold-over from earlier. Expanding it into a proper drift mechanic sounds cool, though!
Thanks for your feedback, I'll check your game out shortly :)