Thank you for the detailed feedback! I hadn't considered making the controls looser, giving turns inertia would be the first thing to try I think. It could result in a much more interesting experience and it would have fit the theme better.
Unfortunately I wasn't able to find a playable version of the original old Asteroids game online. I had to settle for some similar games for my inspiration. I probably could have had I looked harder, but I didn't want to sort through the other 100 games that decided to name themselves Asteroids.
Difficulty is definitely something to be improved on. I agree that it is much too easy as it stands. I had planned to increase asteroid spawning or speed with time, but when combined with the added difficulty when you lose a control I felt it would lead to an exponential difficulty curve. While thinking of how to adjust spawning to account for parts lost I forgot about it entirely and ran out of time to add it.