This thing has a great potential!
In the ancient times there are some civilizations which don't appear on the map. Egypt, Gojoseon, , Van Lang, Elam, somtimes Babylonia, and India. And why did you put the beaker culture?
There a also many greek city-states missing..
I also recommand that to add the mesopotamian city states in the 2000-1600 BC, like Larsa, Mari, Eshnunna, etc, beside the babylonian or the sumerian civilization.
I'll try to add all of this, thank you for this great project!