First of all I think the game is great. Beyond some already mentioned shortcomings that are mostly not gameplay related but more graphical and are fixable.
So here comes another one. Player color is to dominant on the unit model which makes units (in particular villagers) look like they are swept in colored blankets. Compare this to the buildings in age IV and I think you could find a sweet spot there. I would under no circumstance sacrifice clarity in favor for realism. But it is currently a bit over tuned and can be further adjusted. Also I think it would fix some of the “cartoony look criticism” since bright color make details disappear.