Hi,
Good work with the game concept and overall execution. Overall improvements could surely be done, but heck, that would probably be a ton of work !
I don't know if I'm really a poor player or what, but from my perspective, one rather little change would improve deeply my experience with the game : make the joystick orientation for steering left/right in world space and not in the car space. It's almost impossible for some of us around there to figure out what is left and what is right in this game when it comes to steer for the upcoming turn. And I was playing micromachine 20+ years ago without any major issue !
Just in case this wasn't clear : if you want to move the steering cursor up-left on the screen, just push the stick up-left. And make sure to make it permissive like use a simple Vec2.Dot() function to resolve the stick direction into steering direction. FInally make that a setting in the game and release a new version ! :D
Bye