Simple but a good foundation
In terms of gameplay, it was fairly simple. There really isn't much to comment on here. I thought there needed to more varied obstacles/challenges, as right now the gameplay is pretty repetitive after a while, and in addition to this I found the difficulty of the rough/risky paths to be extremely over tuned, mainly due to the slipperiness of the car making it hard to control easily. I think the foundation is great, it simply needs some more content to build off of.
Visuals were good for what they were, but pretty barebones. I really liked the lighting, that was really pleasant to see. However the appearance of the actual game components were really barebones, typically just one solid color, which looked a bit boring. I can understand making a bunch of high quality sprites can be time consuming, so something to do to compensate is to add random props to the side of the road (ex. Trees, Bins, Lamps, Benches, etc.) which would make the world feel more complete.
Audio was very barebones, and what was here was pretty repetitive. Adding a simple background track would go a long way here.
Theme use was very good! I thought the idea of having to pass a long distance, with a risk/reward element to get their quicker was a great concept, and it had a solid execution here. Very well done, this was probably the strongest aspect of the game.
Overall, while pretty simple, what is here is still pretty enjoyable!