Good concept, but it just needs some polishing.
Very simple and intuitive controls!
I recommend interesting things like branching paths, ones with ramps and one without. Maybe that indicates the harder but more rewarding path. Also, if there was a speed control of some sort (scroll wheel or phone tilt) that would make the start a little more interesting and reward skillful play.
The upgraded cars should have other benefits/trade-offs rather than just increased point reward. Perhaps have some that are faster than others, or some that could float momentarily in the air to prevent the first mistake being a deadly one, etc.
The color of the bridge changes needs to be tweaked. The red color is difficult to see the right edges because the bridge top and the right side of the bridge are the almost the same color. This is ESPECIALLY true of the blue area. I was very disoriented trying to get through that part each time.
Sometimes, there was a bug where one tile of the bridge didn't spawn, leaving me with a one tile gap that was impossible to cross. My only option was to drive off the cliff into the water.
Make some minor tweaks, add some music and some sound effects, and you've got a cool mobile game! :)