Unplayable with a french keyboard. It would have been fine to allow also the arrow keys, for example.

When I read "racing game", I expected a fun and fast game like Mario Kart. Instead, even trying to steer my vehicle required a steady hand, and -- as you point out in your description -- the game turned out to be a real test of patience as I progressed. The only thing that helped me keep my temper was the great tune. As a single downside, resetting the player to the beginning of a level after hitting a red block seemed a bit too hard for my taste.

controls are oversensitive which frustrated me, the exposure/brightness on those wall blocks was distracting and a little too much.. but still a kind of "let's try and get better at this" type feel to the game..

Not too bad! Really impressive offering for a weekend! I have two comments- one, the volume was a little loud, and two, the controls were just a little too fishy. Otherwise, I had a blast playing it!