It should also have more npcs, just so it doesn't feel so empty. Plus maybe a notoriety sytem could be implemented. Cause too much trouble for police or npc gangs and they'll come and try to kill you. Hide in a gangster area to get away from cops, hide in a cop area to get away from gangsters. If you get killed by a cop, you go to jail. If you get killed by a gangster, you go to the hospital (albeit for a shorter period of time). And maybe you could apply seasonal tilesets to the map at will.