Saya no Uta

The synopsis does a great job at explaining the basic concepts. I rather not spoil the story. Though the game has depiction of sexual interaction that may scare off most before even finding the true horrors of the story, and once you start thinking about then their true horror unfolds latter. Its called in slang freezer horror or cooler horror as it starts to reveal its true terror after you quit reading.

The story is made to make you feel uncomfortable, laws are broken and then pushed in it both legally and morally, you can even say the laws of nature. These laws being broken especially the morally/social laws really push you. It should be noted you should go into this expecting a level of disgust of which adds to the atmosphere and truly makes the story as well as gives life to it and the characters. Also it had some lolita vibes, which I can't say it is comfortable, but thats the artistic intentions.

Yeah its also extremely beautiful while also being gross which is strange. I feel the story alone should make up for any concerns that may be given, which as noted its not unexspected to have something make you uncomfortable or trouble you, trust in the story.