I read a brief profile about your goal of creating your own game. I do have a suggestion but it fall in the category of find a need and fill it. A lot of games out there with all kinds of goody's. However I have looked long and hard for many years and have not found a simple car driving simulator, lots of stuff on flying air craft but it would be awesome to any parent to have there teenager new driver to just drive. Must pay attention to signs, lights, direction, slow traffic, fast freeway, and different levels of hazards and random events. The out put score chart could be presented to a parent of sort for a formal proof that at least the new driver has successfully completed different levels. Adapted kits could be foot peddles and instrumentation but the view is locked to the drivers seat, an option could be right, forward, or left view that could be switchable or even projected on a three separate monitors for view point if multilabel video card were present. The controls could be simple USB inputs to mimic mouse, joystick and such. Some like this could extend you ability to capitalize at mutable fronts.
Like ....
Parents would pay for it not a penny pinching kid who just wants the new game
Insurance could give discounts on high score levels
Hardware controllers are simple and cheep to construct, most technology already exist
just remodel the shape into peddles and steering wheel with USB inputs
any way just throwing that out there