Thanks for checking the game.
As
Tiur said, the Acts are narrative and not "season" splits. There will be season splits (because of growing download size) but they won't coincide with the Acts.
It's easier than that, perhaps I misexplained.
Christine's personality and dialogue will be different if you are on her negative side. If you have a full harem when she arrives, she will start with -21 Relationship Points and will be bitching about how you are treating the women as objects for your pleasure instead of as individuals. She doesn't know the MC and hasn't seen the harem blossoming. When the (two) option(s) to open her path shows up you must have positive RP for it to show, the same as the other students. There will be enough choices to get the RP to the positive side before the first choice even if you have a full harem (Debbie's range right now is -16/+24 RP, Kim's -11/+20, and Lisa's -7/+17 for example and there hasn't been a hint of relationship yet). You won't miss any lewd scenes if you open her path on the second chance instead of opening it on the first one.
If you open a path with any of the last batch's girls, it won't have a negative impact on your relationship with her. She has witnessed how that relationship has evolved and has discovered you are not the hoarding monster she tough you were.
Monstergirl? Mmmmm... No, not she.
No bad endings in My Dorm. Every girl (and the MC, and at least four side characters) will have an ending. For the girls, I've thought of several ending categories and there's no sad ending:
* Is the girl with the MC?
- Yes: Very happy ending.
- No: Happy ending (having a "big family" with resources helping you to achieve your dreams can be good).
* Is the MC alone?
- Yes: Mildly happy ending with everyone focusing on their careers/businesses. For me, this is the worst ending.
Modifiers (if the girl is with the MC):
* Is the MC on a monogamous path:
- Yes: Very different ending.
* Is the girl pregnant or the player has said he wants children?
- Yes: Ultra happy ending in most cases.
* Is the MC in a relationship with any family members?
- Yes: Changes the ending for some other girl to an even happier ending.
* Etc.
The new girl will have enough chances to join the harem and recover the negative RP she starts with, even with a full harem in place. If she was Debbie, she already could be on the positive side. She only needs to watch the harem work to shake their prejudices off.