Nice quiz! But also, were there really no civilizations in Sub-Saharan Africa or South America (like the Andes) by this point? Or is it just that, if there were, we are unaware of them (due to, for example, the use of oral history instead of written records in these places)?
Likely both, but I couldn't find any further information for these regions. It's also very likely that there were more entities / states in Mesoamerica than shown here.