Hearing all these comments and posts made on this game in 2019-2020 makes me glad I'm not the only one who recently got into this game, having just heard about Sayooshi last week.
Anyways I think many of your points are valid. I agree wholeheartedly that the H-scenes are over-the-top and were most likely added for shock value. It gets to the point where a good number of these scenes become drivel, almost filler to pad the game. However I would disagree they are completely meaningless given they are strongly reflective of the protagonist's deteriorating mental state and do bear some signif