It all depends on what you expect from this kind of VN. This is not a literary masterpiece with deep characters and a masterfully crafted story, but as an adult game, I think it's very good, especially when compared to others here
It has a more complex, ambitious, and interesting story than 99% of the VNs you can find here. The dialogues are fine, the dev doesn’t try to be pretentious or deep and end up being cringy. The update frequency is perfect, in other good VNs, you have to wait 6 months to a year and that's crazy. Okay, the dev probably has to sacrifice something to provide such frequent updates, maybe less detailed animations or renders in general, but personally, I don't care about that, and the LIs look good. This is not a book, it's important that you can insert yourself into the story, and the choices must matter and in this VN, they really do, you have great control over where the story goes. There's a good balance between rewarding the player and not making it a stupid game where you can’t get any scenes just five minutes after starting.
It's true that the English might not be great because it's not the dev's native language. It's not my native language either, so most of the time I don’t even notice if the writing is bad. I guess for a native speaker this might be more annoying though.
Anyway, this VN is not for everyone, and that's fine. If someone doesn’t like it because they aren’t interested in the characters, medieval fantasy, quality of animations, quality of English, or incest, that’s understandable. But compared to other VNs, I think it should be considered a top game.