This is truly wonderful. Is there a way I could generate a city and then take parts of it out as FBX to use in another game?
Yes, you can. Download the source code and open it in Unity. Then you generate a city to your liking. You need to figure out a way to export it. There is a free FBX exporter on the Asset Store, hut I haven't tried it. Let me know if you encounter any problems.