Thanks for playing! More tracks are definitely something I would've loved to add, I just didn't have the time, unfortunately. That's an interesting idea about the pickups, which I'll definitely have to think about... Although at the moment your speed does incrementally every loop, making the car harder and harder to control, which is the slight increase in difficulty I put in the game. Unfortunately, I don't think it's actually noticeable unless you play endless and get to like loop 30+
The enemy car isn't actually designed to overtake you, it's trying to catch you. It's basically only there to stop you from driving super slow and collecting every coin easily because if you try and do that it will just catch you and you'll get game over.
Hmm... The music should work, it works for me and seems to be working for other people. You may have pressed "M" whilst playing? That's the button for muting the music.
Thanks again :D