Something else I was wondering about, you need to seduce (and thus betray) multiple girls just to train your skills in the base game, but you'll already have those skills in NG+, so will it be possible to get a pure single-girl ending there? I think currently, assuming you have all the skill and knowledge flags through NG+ you'd still need to seduce Nell and Lilith at minimum to win?
Well, first of all, you won't actually betray anyone unless you deliberately become their boyfriend. The biggest reason that is a problem right now is that charisma is tied to reaching a romance state with one or two of the girls (Evelyn and possibly Samarra), and you need every point the game is able to offer you. In the future, you should also be able to obtain charisma from both Callie and Sister Agnes, and I will make sure not to require a romance for that. I also suspect I might rethink Samarra's results a little, which should hopefully mean you can gain charisma there without going all the way with her. So, by the time this game is complete, you should be able to pick one girl and stick with her without breaking the heart of anyone else.
It will never be possible to complete this game while only having sex with one of the girls, however. I did put some thought and effort into that idea earlier in development because of player feedback, but I eventually had to put that concept aside as it conflicted too heavily with my planned story.
The purpose behind the open-ended nature of the game and the time limit was always that the player would have to pick and choose what to focus on, offering multiple ways to go about things. It's supposed to be really difficult (but not impossible) to have sex with all the girls on your first playthrough. You are supposed to pick a favorite, but it was never my intention to have the MC be entirely faithful to her. On the other hand, you're not expected to make promises you can't keep, so as long as you make good choices, nobody should be too pissed at you at the end.
