This is a really cool concept! There were a few things that bothered me with the execution, such as the screen scrolling making it difficult to line up my shots with the car and the obstacles could all be cleared off screen before starting. I think it might have been nicer to have hitting the sides slow you down but not send you back to the start of the level, and then have you race against the clock or another driver instead. That way you can complete the level after making a few mistakes, but can come back to get a better time as a reward for not hitting the sides.