There is this mini flash game called rack, in which you have a range of subjects and you have to do these tasks in order to unlock further content, which are more toys, features and subjects.
The subjects all have different likes/dislikes, where one girl prefers anal, another likes vaginal. One likes forced orgasms, another orgasm denial. one chick wants you to come on her, another likes it in her mouth. Some even get off on looking at another pleasure or pain.
That could be one cool feature to include in this game, because as we know, everyone craves different things.
I'm thinking maybe it could be done with mood settings...
Another feature of rack is an aphrodisiac, which if given to a subject, you can pretty much re-wire them. Take for example a girl that hates anal, starts liking it after being given the aphrodisiac, and after further use, starts loving it even without it.
So you can always use that method to have it your way.

Do you have a link for the game you mention?

Edit: I've found it. Unless this is a different one.
http://www.comdotgame.com/play/rack