The idea is nice and original and the elaboration is good for the most part, but it can become boring and repetitive quite easily. Some more variety would be great (maybe some ramps where you have to be quick to get across or maybe a tunnel?), but I can understand that it was hard to make because of the time restraints. A backmirror for seeing cars that want to crash into you from behind would also come in handy.
But on the good side, the control(s) are very tight and responsive (it also took me some time to adapt to the fact that the down arrow doesn't actually mean brake, which lead to some funny moments :) ) and the game looks and performs great. The city also looks incredible with some interesting buildings and the turning system is really interesting. Good job!