This game is definitely a one-of-a-kind.
TL,DR: Clever, deep, and self-aware writing, some good Koikatsu work, and wonderful characters.
The writing! The characters are so endearing that I went from "ok, a new character" to having feels about them faster than any other game I can remember. The plot is convoluted and a little messy, but it has enough internal consistency that it works. There is a lot of humor, and it's a good blend of over-the-top and subtle nods.
Smut: It's a slow burn-- there is a ton of lore, world-building, character development, and plot to chug through. But the content really does deliver. Top-tier writers of H-games tend to be very adamant that their game is a Serious Game, not fap fodder, and the porn is just there because the plot needs it. Well, so be it; porn being secondary to plot is certainly true enough for those games, and for this one as well. But I get the vibe that this game is not ashamed of being sexy, and is willing to have a lot more fun with the h-content. That's a huge plus in my book.
Technically, the game is remarkably bug free and runs on what is best described as a nearly-full-featured RenPy engine built inside Unity, complete with a robust save system, rollback, ctrl-to-skip-already-seen, etc. This lets it have some things in it that you couldn't pull of in RenPy, mainly a so-far-little-used, but interesting, combat system.
The downsides: Like with most KK games, the quality is a bit spotty in a few scenes, especially in close-ups. There is a large (but not huge) cast, and all of them have multiple names, so you get a lot of information pitched at you early. (Fortunately, the characters are visually distinct and have memorable personalities, so this is not as bad as it sounds.) None of these flaws are big enough to deduct a star, though.