After a couple of hours of game I got some idea : Make the money more usefull. The possibility to get money doing some work in the game. Integrate the Experience Points in the game that can allow your avatar to do extreme sex position and more option in customization. Create some dark, dirty location... everything look too much clean in the game. A Clinic where you Avatar can get big lips and boobs would be a nice way to make the money more usefull and add a way to get more extreem customization.