Not a bad idea, but once you figure out how it works it becomes very straightforward. It's less that you are building a track, and more following a line. Really the only reasons I lost a level were when I didn't know which way the car was facing and when I mis-clicked. Having a selection of tracks pieces might work, or maybe making the player drag and drop the pieces? Not sure, but it definitely needs something to up the challenge. 

Perhaps instead of the game always giving you whichever track piece you need, you should have to pick it from a few options