I want to give this a higher score, and I don't know if that's just personal taste or because I want to commend the author for doing a few things really well, things that can be rare in the genre.
For one, it's actually finished. Yes, it could have stretched into a better story, but there's enough here for multiple acts, a rise and fall, and a sense of resolution. Some paths feel more dramatic than others, and that's ok.
Which relates to the second point: the narrative splits into completely distinct branches. There aren't very many moment-to-moment choices, but the choices that exist can change the story dramatically. The consequence of this structure is that many choices are obvious branching points, and it's a matter of choosing story A vs. story B, although some choices are convincingly obfuscated.
The writing is good like old usenet erotica was good. It has a voice, it does some writerly things, it occasionally evokes some real menace and conveys a feeling beyond horniness. Most importantly, the forward momentum of the story comes from the porn itself. watching the characters change as they react to their situations is part of the porn appeal.
The game works best in the first half when it's focused on a few of these characters, keeps the situations intimate. The bigger the story gets, the more rote it all feels. Punches are pulled, new, purely functional characters are introduced to wrap things up. As some other reviews have pointed out, there is a palpable sense of impatience from the author. By the end, it's obvious that he's ready to move on to a new project.
Hopefully, the next thing the creator works on will display more passion and commitment in its art and story, but this is a promising start to what will hopefully be a long and fruitful career.