Really cool aesthetic. Managed to figure out eventually what I was meant to do after reading the description. Perhaps for people who don't tend to read descriptions, a simple on-screen prompt before the game starts to explain the aim.
Also I mostly disagree with the comment about feeling like you're crawling around - I think the whistling sound and ship wobble as you pick up speed do help to give a sense of speed.
I think it'd be cool if the camera rotated slightly with the ship as you level the ship out, just to improve visibility a bit.
Pretty darn difficult - I like it!