It's important to consider that while designing games is extremely difficult, and making them profitable is even more difficult. It should never stop you from coming up with great ideas. Whatever you have let's hear it, lets share them and from there you might be able to refine your concept so that it can become something a bit different that works.

I truly believe in the power of motivation rather then ideas. Millions of people have ideas every day but only the truly motivated realize their dreams.

If this idea is your dream then you need to get to work on defining it clearly, determining exactly your needs and wants, finding the people you need to make it happen, motivate them to work with you by being clear about your dream and moving things forward with good momentum.

Good luck !

I think procedural cities are cool. A lot of the difficulty, though, depends on what you can do with it. A bite-sized approach would be maybe to start with the idea of precreated tiles and do something with that, such as some sort of timed city builder or even a GTA 1. You might then branch out to randomization of each tile. Then you might zoom in with the same idea, making buildings that are, in effect, precreated room tiles / chunks (like boardroom with bathroom combo). You can then branch out and diversify the gameplay.

There are a lot of technical issues, of course, but taking steps toward what you want to make might benefit from pretending you're in a different time, with more limited technology. For instance, busting yourself down to a text-based game could show you how to deal with adding gameplay on a node-by-node basis, which could lead to visualizing the city as collections of nodes, which THEN could fit nicely with the tile idea.

Doing this might help demystify things and help you set inspiring targets on your way to where you want to go.