There's a bit of improving to do, for example some transitions feel awkward. Either way, the game is something you wouldn't find on this site. Porn games tend to introduce "tsundere" characters that fall for you in about three scenes. That's why I advise you not to rush things. You are treating complicate matters and the atmosphere was well built. You don't have to "break" this dooming/depressing feeling, you have to evaporate it bit by bit, this way it will feel natural when the characters break through their problems and fights. Of course a cathartic moment is needed, but again, there is a lot of build up to make here.
Another thing I would recommend is that you don't use the girls like livestock, that's something almost every game does, even the best ones, because they cannot escape from the banalization of feminity that comes from the fact that their purpose is the sexual pleasure for the male audience. Not only they should be opposed to sharing, they should oppose you in a hell lot of decisions. Make it ugly and worth it at the same time. Try that the mc isn't the center of attention all the time, life is not so easy that you can have a group of girls drooling for you and they are okay with it. If you want that end, there should be a lot of fight in between, and it shouldn't be a fight for the man all the time, but for themselves and for other people they care about. You got the perfect vn to pull it off.
Some input about the characters, not saying it is good or bad, just my impression so you have a major view of how some people may react to your story.
1. I hate Miranda. For some reason she thinks making mc's life miserable is worh it because it's a lesson of some sort. Talking from experience, this kind of lessons are crap. If you can stop someone's life going to shit, you do it. The lesson should come from a direct teaching, not from ignoring the issue and putting the blame on the victim.
2. I feel bad about Junie. I know MC just wants to have a good friend, but he is being kind of an ass. If he doesn't like her, he should tell her. If he doesn't reject her he's just extending a relationship where Junie is obviously expecting an ending MC can't give her (at least from the present point of view). Maybe I'm lacking the full picture, time will tell.
3. Both parents are crap. Any try to sympathize with them is useless, at this point they have no redemption. It doesn't feel right when they talk "honestly" like they have accepted their situation and that's about it. The sisters are being insensible when they just let all that shit happen, and then they talk with MC like nothing's wrong. Like they are not part of the issue. The house has some deep problems and I hope they are addressed because oh boy there's a lot of hypocrisy in there.
4. What the fuck is wrong with Victoria? If the situation was different, the scene would have ended terribly. Both siblings scarred for life. Then the cunt tries to put an excuse because "she wasn't feeling well". Feeling too much bad vibes about her, Audrey shouldn't forgive her, she did something too fucked up. Horrible friend.
That's the opinion I can give you as a player, hope it helps. The game surprised me and I may support you when I get a clearer view of what you are planning here. Best of lucks.