I have two gameplay suggestions: one Apartment and Commercial Building should be able to charge rent for retail spaces just like shopping malls, and the player should have the same availability options as shopping malls, as in space is open to rent to player-owned stores only, or any company.
The government should be able to integrate government services, such as schools, libraries, and museums, into the retail space of apartment buildings and commercial buildings, both government-owned and privately owned. Yes, shops should have to pay rent to occupy that space. Also the retail space of governmemt owned building should be open to rent and generate revenue for governemts.