The idea has potential, I could see it being pretty fun. WHen I played I never got past the stage of 1-2 cars, it takes a long time to get through a day and to watch tens of empty cars go by with no income. I would suggest making it easier in the beginning to get things started. Impressive that you did custom art and everything! Wonder how you managed the physics, that was a pain for me (I also did a rollercoaster-y game) :)