I ran into some of the same issues as below, but I enjoyed the concept of an open-world graffiti game! Being able to jump so high in the car is a lot of fun
If you're interested in pushing the low-poly aesthetic, I also saw this video recently which talks a bit about how geometry can be made more efficient - specifically in this example, using the same number of polygons for cylindrical shapes while making them look much rounder and less boxy