Played the latest SimBrother v2 version and it's really good. Maybe we can grab some ideas from there.
-The game has a big part of it's gameplay devoted to the player's interaction. Every day do you get a fixed number of Action Points (AP). Actions of the player in town require one AP each, for instance visiting the shop, the slave market, visiting locations (you can search several places in a location and sometimes find a bit of items and gold there, but it's more like a gamble since in 2 of 3 cases won't you find anything) and interact with girls.
-Instead of instantly hiring the girls in town for your brothel, you first need to romance them. Every location of the town has different girls available and the girls change their location every week. You start as stranger and have to lure them with smalltalk, jokes, insults, money, gifts from the shop, touching and kissing to become your girlfriend. Afterwards you can have sex with them and/or try to hire them for your brothel.
-Each girl has different characteristics that decide what kind of things she likes and what she doesn't. Attributes are "religious", "nerd", "slutty", "meek", "stylish", "lolita", their hair color and many more. Slutty girls will like it if you insult them to be a slut, religious girls don't like it if you talk dirty and lolitas prefer jokes on a "kids" level rather than the more complicated adult ones.
-When customers come to the brothel, each of them has an exact desire that he hopes to get pleased. Usually those are in the form of "Customer A wants a [handjob] from a [religious][nerd][blonde][none] girl. Whether or not the customer will be satisfied after his visit and increase the reputation of the girl and building depends on how many of the desired attributes a girl fulfills that is working there at the time of his visit and how good her skill points are at the chosen discipline (handjob). The more attributes match, the better the outcome. However, the girl still has a random chance to make the customer happy with her charm, depending on the amount of skill points for that.
You can assign one specific style to the advertising of each individual building, allowing you to control a bit what the customers want that will enter a particular brothel and thus making it more efficient to group girls of the same style in the same building.
-Girls also have a skill tree. Gaining XP and leveling up will occasionally award a point for that skill tree to the girl, so she can choose special abilities like "Naturally wet: Never needs lube", "Super tight: Sex with customer will always give at least a satisfied rating", "Lucky: May randomly find money when taking her time off work", "Girl is friendly and gains +1 charisma", "Nurse: Other girls in the same building heals faster". This is additional to stat points that can also be spent freely and are earned with every level up.
-Projects: Big projects like creating a book, calendar, photo session or movie cost a lot of time and money and need the player to work daily on them, as well as occupying a certain number of girl for the time of their creation. The stats of the involved girls influence the quality of the result.
-Not all brothels are equal. The first is just a wooden shack and has space for maximum of two bedrooms and a bathroom, which needs to be build separately. Later will you buy a cave which is suitable as dungeon for BDSM sessions. Before that can't you satisfy the [Fetish] demand. Once rooms are added to the building, they can be further equipped with better furniture. The old shack has only straw beds available and a bucket of water in the bathroom for slightly increased hygene level, but later houses allow more expensive furniture and more rooms like bars, casinos and so on. You can also buy way more buildings in that game than here, but they start off really shabby and you need to work your way up instead of starting with a real house like here. And things become really expensive in the end, but that guarantees a long endgame.
-It even has some kind of story goal: pay back a depth to some mafia guys. The dept is $500k and you have 5 years.
