This is absurdly high quality, but unfortunately it doesn't work for me. The big issue is a common one I have in choice-based games that deal with serious themes: disassociation with the PC. I'd be cool reading about a character with no player agency whatsoever, but if I'm expected to shape the narrative with my own interests and values, I'm never satisfied with how far it goes. I even think this story does it far better than most, with choices that go into a little more detail into the PC's thought-process. But especially in "the scene" with Isabelle/Heather, and particularly Anja sharing her mentality with you, if you can't make a meaningful choice at that point then I kind of check out of any player involvement going forward.
I admit I probably wasn't going to love this game anyway given the material. I like exploring boundaries, not breaking them. Any comparison to Starless is a red flag. But like I said this is a very high quality work with a lot of thought going into the characters, writing, setting, and visuals so it demanded my attention nonetheless.
My other problem is a minor suspension of disbelief issue. Here in America, debt does not transfer to relatives. Maybe the game is set somewhere else, or the law works differently in the setting, or maybe even the PC was intentionally misled. But I'm left thinking he got himself into this situation due to gross ignorance, which is probably not the best introduction.
EDIT: I also wanted to mention that I was very surprised in "that scene" that you set yourself up for an "out" but didn't take it. You ask the player if they're into that, then the PC monologues that they need to see if Isabella is bluffing or serious about it. I was very sure that choice was going to influence which one she was: you're into watersports, it's real, but if you're not, it was a power play to see how submissive Heather was. Not sure if you felt that a route split so early on would be too much of a headache going forward or if I totally misread your intentions.