Thanks for playing!
There's definitely a good case for this to be a proper level-based puzzle game! In my head I was aiming for something closer to Tetris, where the increasing length of your train, the moving cars, and the random elements crank up the tension as you go.
Glad the game was playable for you, for some reason on my end, Unity shrunk the game screen to a postage stamp, and it can't be resized.