I've been spending some time with this game and have managed to build a city that takes up roughly half to 3/4 of the entire map. It includes a couple of nature/forest preserves, a major industrial area and a small rail yard. I've included the file so you can download and play it. Mine is in the same folder that comes up when you click "File" on the desktop, but I imagine you can direct the game to look anywhere for it. Also, to be able to upload this, I had to rename the file extension to .zip. After you download it, rename the extension to .cty
I would welcome any thoughts, ideas or improvements although I can't guarantee I will implement them, though. Enjoy!