Respectfully, given the SHEER AMOUNT of heavy/dark content in this game, I think it's in drastic need of some trigger warnings. I wasn't put off by any of it myself, but there is SO MUCH both shown and implied for certain themes that I feel you really should put something, somewhere, so players who may have potentially been through certain things themselves don't have it dumped on their lap unexpectedly... after all, there's a vast difference between what one person is able to handle as "dark" or expects, and another, especially in a game that's so aggressively heavy in certain aspects as this... and no, I don't mean the gore or sex. :)
Other than that, I did enjoy this. The conditions for some of the endings felt a little arbitrary, at least so far as "why does X lead to this ending and not Y", and the big plot twist was sort of predictable, but I liked the cast a lot. I was really impressed by how expressive the characters were, there was so much detail in so many tiny tweaked character expressions that it made them all feel distinct and real. The atmosphere in the scene where Rosa was searching the room in the dark was absolutely fantastic and beautifully terrifying. Sound tends to get neglected in a lot of visual novels, and you did some great things here with yours. It's a little disappointing that so much of the villain's character and motivation is only delved into if you get that chapter seven for the bad endings, because I feel like it really sheds some important light on why they are the way they are, versus simply being a "monster", and it helped me understand them and sympathize for their cynicism far better than the long winded ethics conversations in endings one or two. But it's still a very well executed and engrossing visual novel, and I hope we see more from you soon!