1. The mandatory "totally not incest, we swear". There's only one route and it stinks. No one's fooled by "they have different parents, honest injun" any more than by the "they're 18 or older, honest injun". Hina doesn't stop calling Yuna "older sister" when they become a couple. There's never a consideration for them living in different households, Yuna never goes to visit Hina or communicates with her parents. Growing up, my classmates' parents were always a presence, even though I was (still am) an autistic loner. Sure I'm older than them and grew up before cell phones, but they're so uwu kawaii close they each of them effectively has two sets of parents. Parents should be more of a presence in their lives, not less.
2. The rapey shit. We've got statutory rape, sexual harassment and molestation of a minor, and sexual extortion and abuse of a minor. All of it is portrayed as uwu kawaii.
3. Unlike a typical vn with routes, here several stories happen at the same time, and all romances are backloaded. Action never risess or falls, it simply plods toward the inevitable pussgrabbing epidemic.
4. Repeated content. Some scenes are repeated from another character's perspective, but little to no effort is spent paring down repeated dialogue to keep the content fresh. None of these juxtapositions reveal any interesting conflicts, misunderstandings, hidden motives, or dramatic irony.
5. The choices are boring and have no lasting effects within the story; even worse, trying every single one of these inconsequential choices is required to unlock the b-side (about 1/3) of the game. This is worse for characterization than even pure linearity.
6. The biggest thematic problem is the incongruent mix of ecchi fetishism and uwu purity fetishism. Lesbian sexual attraction is sexual attraction. It's an adult game that wants to show tits and such; fine. But then, not only all pairs match (lesbians aren't all attracted to each other, you know), not only everyone is a lesbian, but the attraction has this cutesy uwu pure sexless quality until the sudden but inevitable pussy-grabbing. "Oh ok, you're nice and I don't want to be rude, I guess I'll date you."
7. No one's experiencing or even anticipating any realistic trouble. What if the other girl isn't a lesbian. What if she tells the teachers. What if she's not into you. What if she already has a crush or a girlfriend. No conflict, no drama, no meaningful interactions between members of different pairs, no surprising romantic outcomes. These are the pairs: now wait for them to fuck.
8. The lead character is supposed to transform from a loner to a popular girl, but because of no interactions between pairs she starts out with no fewer friends than anyone else in the game. She goes from a normal, well-adjusted person with two close friends to a self-effacing attachment deficit sufferer.
9. No school. They aren't shy about characters being children, despite the disclaimer, but the fun of child characters comes from the convoluted, artificial environment of the school and academic curriculum. You're fucking, or fighting crime, or travelling to other dimensions, but you still have to get good grades and come home by dinnertime. Growing up is seeing meaning behind the structure. Here, all of school is just filler.
9a. No parents.
10. Girls can't math. There's only one math club member, and she just wants to fuck the advisor (who's a literature teacher, because girls can't math). Why aren't there any characters with gender-nonconforming interests in a lesbian game?
11. The highlight of the story is a character who's an escapee from a different story. She's brash, she's loud, she's got no tolerance for uwu drool, she's here to kick ass, take names, and grab her lady love by the pussy. She's awesome, but she makes it even more obvious that eveyone else's character and sexuality may as well be a protracted how is babby formed reference.