I've given about 5 or so games a 10/10 in my life, and three of them weren't Visual Novels.
The action in the story picks up from the get go, and snowballs down a rocky, tree-covered hill. We start with Takumi the fagbitch, we run through with Fagbitch, and we watch him go from Fagbitch to Hero. Yes, it's a little cliche, and Yes, his Bitchiness is hard to deal with, but by the end of the story his changes give you a true sense of having been there to watch him grow up.
The Heroine cast doesn't disappoint either. Every niche is filled without overpopulating the moe-ecosystem. Nanmi the little sister (She IS moe, you little fagbitch.), Rimi Onee-chan, Kozu-pii...err, fuck, Kozue the squeeky Loli, Sena the domineering Tsundere, Yua the klutz, and Ayase the endearing head case all come together to carry the little bitch through his nightmarish delusions, and yet never impede the storytelling itself. His imagine Ero-scenes were a welcome bought of hilarity amongst his mid-story paranoia.
And, against all hope, Takumi actually manages to mature into a Hero, going so far as to slash his beloved Seira-tans to little bloody bits.
Got what was coming to her, as far as I'm concerned.
As for the suspense/horror-ness of the plot, that was wonderfully done. As each tidbit was revealed, takumi's, and our own, expectations of who to blame rapidly shifted around a list of suspects. I'm not entirely sure who thought of going for the oft-unused element of kicking the horror aspect to the curb and giving Takumi a weapon he could use, but it worked out great. That Final Battle, short as it was, was epic. I wish the Di-Swords had seen a bit more use, but the disuse actually lended them an aura of "Last Resort", rather then "Super Weapon".
And, even the ending was satisfying. Which is rare in a VN.
Now, on to B route.