This game is amazing. It has great writing, likeable characters and interesting worldbuilding. The gameplay oscillates in quality in my opinion, as I don't particularly enjoy the poker thing going on in it, but I do appreciate and respect the effort that went into designing the system. It is not without its flaws, however.
If I had to hone in on the most fundamental problem that the game has it would have to be the porn. Much like Sorcery, porn is a double-edged sword. It seems strange to say this on this website, but it is undoubtedly true. The game has such fantastic characterisation (in most characters, but we'll get to the other problems with that later), that its honestly frustrating when the main character is reduced to acting like a crude horndog for the sake of creating drama / porn, and when half of what other characters say to him revolves around excessively suggestive talk which really isn't appropriate to, say, a war council revolving around attempting to save all life on Earth and Elsewhere from a horde of ravenous immortal cthuloid monsters. But the game almost feels obligated at times to remind you that it is in fact a porn game. The sex itself varies from great to subpar, but I wouldn't recommend this game as a sex game first and foremoremost but rather as a story game that features sex. It doesn't help that the characters with by far the best designs imo (Xochi, Val and Kath), have a sincere dearth of content for this key component of the game, having a grand total of one actual scene between them.
The biggest casualty of the porn game tropes is certainly the main character, though. He is ostensibly a wonderful guy, but the porn game logic dictates that he takes many selfish actions, both in building his relationships and in bed. The fact that it is explicitly called out by both others and himself makes it rather awkward that he never changes this behaviour or even really considers doing so.
Amongst all the great characters though, there are a few that really suffer from weak characterisation, lack of direction, or a lack of content (and in one case, all of them). The chief perpetrator is Emily, the main LI and secondary lead for the story. While the role she fills in the story is solid and occasionally interesting, she herself is just a tad too bland to compete with the much more dynamic characters in the story like Chloe and Molly. But while Emily has good characterisation scattered across all three Books, another essential character, Katie, starts strong in Book 1 but gradually fades to roughly the same level of relevance as token healbot sidekick Dylan, only with sex attached. Finally, much as I try to like her, I can't really say I was particularly attached to Akane (another main character), as she lacks much of a strong personality, much content (especially early on), and whose plot beats are almost always shared with other, usually more interesting, characters.
Speaking of the Books, I definitely find Book 3 to be the weakest of the set. While its ending is strong, I don't find it to have added a whole lot over the resolution of Book 2 as most of Book 3 is spent in a superhero-esque timeline/multiverse/reality hop which spends a lot of time re-covering ground already thoroughly explored in Book 1 and 2. While it certainly adds to the story, and brings the story from a more bittersweet ending which Book 2 seemed to be leading towards into a more wholesome and happy ending, I don't feel like what it added really deserved an entire additional Book. Personally, I would have cut the entire reality-hopping storyline and instead split Book 2 in half, folding in the narrative beats from Book 3 without wasting time re-building relationships that were already very strong and interesting from Books 1 and 2.
For clarity's sake, these criticisms are constructive only. I adore this game, and wholeheartedly recommend it to others. It is a fantastic power fantasy and a fun take on the chosen one trope, and I have played most of it twice already. Yet like any game or story, it has its fair share of flaws that must be considered in any fair review, and it is much easier to talk about them than it is the innumerate strengths of the game. I look forward to the dev's future works.