Not bad, quite a lot of fun and pretty challenging, considering the fact, that you have to always switch between the both cars and be pretty much a Multitask master. I guess this game was originally intended for mobiles, but I just want to let you know that it's harder to switch between the both sides by using the mouse instead of the touch controls. I would probably use A and D for the blue car and left/right arrow for the red car.
Other than that, pretty neat, little concept.