While I like the style and art of this game, I don't really like the author's "theme".
All the works that I saw from him thus far always put the sub as distasteful and reluctant of the sexual encounters. This can be seen in this game when there isn't a single scene of the MC having an orgasm. There are dialogues that he "might" be enjoying himself, but he never confirms it nor does he actually cum.
While I understand that this is a rape fantasy at it's core and non-consent is a matter of course, from my perspective the fantasy of being raped only works when you demonstrate how it is also pleasurable. That's why the "assaulter" is always hot. Very few, if any, people have the fantasy of being raped by an ugly person while feeling no pleasure at all.
At the very least, show the MC having an orgasm during it: He doesn't want it, he denies feeling good, but he cums anyway.