Boy oh boy, watching the relationship between Kaitlyn and Marianne unfold was like watching a train wreck in slow motion: Even as you look ahead mentally and know that it's only going to be a nightmare for everyone involved, you can't tear your eyes away from it, heheheh~
This VN does an excellent job of showing how this toxic mess was ultimately the product of both of our girls' mistakes, failures, and weaknesses; that is, the character writing is quite solid, and the subsequent tragedy both hurts worse and is all the more believable for it. In fact, with how strong the characters are—and how their struggles and interactions constitute the heart of the narrative—I can't help but think that the story would be even stronger if some of the drier descriptive sequences were trimmed down a bit, or perhaps integrated the girls into them / were colored by their moods, rather than them being mere passive observers to some scenery that's gone in a moment, you know?
That being said, great work on this VN, doubly so considering that this is your first finished game~!