I really like the visual style, and the main concept is fun! The movement feels quite good; the gathering momentum and speed are fun to experiment with.
I think I saw another comment that suggested a minimap, and I'd agree that it would probably be very helpful. It was pretty tricky to navigate the buildings, especially because sometimes if I accidentally ran into a building while driving downwards, the building would obstruct view of the van, making it easy to get stuck.
Also, keeping the orientation of the camera rigid is an interesting choice; perhaps it adds to the challenge of it, but it was definitely something to get used to!