Neat proof of concept!
I like the monochrome color palette. It's very clean. Honestly, the whole game would feel right at home on a mobile device.
I'd say while the presentation of the game feels very polished, the gameplay is quite lacking. Assuming your theme is momentum, there isn't much gameplay incentive to keep a high speed. Sure, you go a bit faster, but as many folks have pointed out, going slow is much more consistent. The only lose condition is losing control of your car, so why would you ever go faster? A multiplier or speed gate (Be going # MPH or you lose) would help add some more importance to momentum.
The music is nice, and the sound effects are crispy. I particularly like the traffic cone noise for some reason. You should've added some VROOM noises though! As you speed up, hearing your car switch gear is peak aesthetic.
You need more gameplay, but what you've got is very polished and understandable. Nice job!