The controls were way too sensitive.
If you get half of you maximum speed, and if you'll hold either steering button for not even a second, your car will take a very sharp turn. And if you'll try to counteract that sharp turn by turning in the other direction, that will just throw you off the racing track. I had to gently tap the A and D buttons, just to take normal turns, so that I could finish the race. But, after doing the exact same thing 8 times, I've managed to win the game... and then lose it once the car stopped. Neat.
The gameplay needs some real heavy work in order to be playable. I would advise you, to most importantly, reduce the sharpness of the turns, and to adjust the acceleration and deceleration of the car's torque. There also needs to be some more variety in the maps. Doing multiple leaps on one map is fine, but when you need to race through the exact same map eight times, that just becomes boring!
Although, I must say that I liked the graphics. The low-poly models of the map, as well as the car, look nice and minimalistic. With the combination of simple UI, and the slightly modified standard unity skybox, they actually remind me of my own game that I've made for the previous Game Off game jam! So, kudos for the visuals!
The game has potential, but it wasn't well executed here unfortunately. Good effort, but you gonna need to do some fixing and polishing, in order for this game to be good!