I read the entire manga all in one sitting and I'm having mixed feelings about overall story, characters, and ending. Art is great and detailed. The story is completely insane, but I wouldn't say it's the best because there are many unanswered questions such as the legitimacy of the uncontaminated water source that wasn't really explored in detail or even discovered. One biggest factor I will give credit for though, is the themes portrayed. PTSD, trauma, and other related dark sides of humanity stood out to me. I mean, none of the characters are actually mentally well, as they struggle with some sort of severe PTSD or are just fucking unstable. I didn't like any of the characters and hardly related to any of them, but it was an interesting read. I do wish there were some more character development between characters, instead of just "Oh, I feel sorry for you." The MC was already mentally fucked the moment he took on sniper role, acting out his delusions, and I do appreciate the change of pace in villain roles here. There's really no clear evil and that's kind of what makes this manga a unique specimen. This isn't a hero's journey. It's a descent into madness and insanity.