As far as runner games go, it's okay.
There could be more feedback for everything in the game tho - audio for jumping, rolling, passing cars, etc.
Maybe add some visual pleasantries too - particles for when you land (unity's particles are super simple and very effective).
I do not understand how it fits with the theme of the jam tho... Feels more like you made a runner game and then found a jam to submit it to, rather than the other way around :D