As others have mentioned already, some upgrade option for the getting more subscribers per click would be what's missing most. Maybe +1 per car/building and +10 per game phase and an extra bonus when all cars and buildings have been bought.
One bug I could see: When your mouse is over a building/car that you can't afford at the moment, shouldn't it be shaded in red? I've seen them getting green. Otherwise the Linux build worked perfectly fine on my machine.