Not sure if its been suggested before, but I think it would be really cool to have non-square options for building the city walls. (i.e. building walls would function like building roads does currently)
Obviously there would still be a pathfinding barrier imposed on the normal grid system, but the shape of the walls would be allowed to curve just like roads do. I was pretty disappointed to find that I couldn’t create a city that looks like the one on the title screen.