Thank you for trying it and the comments. The prior prototype I was able to add different styles of buildings to help make the time periods distinctive but I had family visiting and lost a good chunk of my weekend development time. (Trying to keep my wife from getting mad at me for sneaking away to work on it.) I definitely want to put the effort in to make 3 distinct time periods so you get the sense you are driving and the city has built up around you or something depending on which time frame you are in.