Well, it's already known that the devs are a fans of ryona and he build this game around that concept. There are tons of ryona / torture H-game in the market out there and many that are more tragic and sadistic than this, but what makes this game is special I think it's because the gameplay, the writing, the animation, the visual presentation, the music and the voice acting all come together to create such impactful scene which leaves us shout oh sh**!! many times. It's apparent that the devs really pour all his passion and thought into this game.
What impress me is that ryona is such a very niche genre in an already niche H genre, yet this game scores a big hit in sales (43K sales in DLsite only) and eyeing a second spot below Crimzon, the King, err, Queen of ryona genre.
If there's some lesson that we can take from this game is, is that people are thirsty for a good games, games that are polished and really enjoyable in gameplay and presentation, one that makes people forget that they're buying a basically torture games. There are so many comment and review of this game praising the gameplay while cursing the ryona scene lol. I myself are H vanilla enjoyer (with occasional NTR tendency), yet I enjoy this game because of how well the devs sewing together all aspect of the games to create one enjoyable gaming experience.
If this game is any indication, I have faith that whatever games coming next from this devs will also be highly enjoyable, regardless of genres he choose. I can't waif for it.