Thanks! Sound was something of a late addition, and the screeching tyres were definitely the hardest thing to get working at all: there's a lead in, a looping middle section, and a fade out that would all have to be adjusted independently (or all set to share a volume variable). By the time I added the single player mode I'd more or less ruled out any more fine tuning, since it doubled the number of places I'd have to go in and tweak things. It's definitely not ideal as-is. If I ever expand this into a more complete game, I'll aim to let players adjust the volume of various sounds.