I need to start this review by emphasizing how incredibly biased I am - I have loved the game that this manga is based on since I was thirteen. That kind of teenage attachment makes you handwave a lot of flaws, and I feel like if I didn't have it, I would've disliked it way more. 

Obviously, it has some issues (pretty genre-typical ones I think); the oversexualization of the teenage girl characters and the predatory lesbian trope in Seiko being the most glaring to me. That said, I love Seiko as a character (not a lot of lesbian rep available to me as a kid, what can I say?) and this manga did a great job of translating the impact of her death. 

Something else I like about the manga is the stylization of the corpses - it's really gritty and gross in a way that couldn't be depicted in the game (though it was described). 

I'm excited to read Kishinuma and Shinozaki's arc next, as it's my favorite. Also I'm fighting for my life trying to get a paperback copy of Volume 4.