I was really pleasantly surprised by this anime.
I went in hoping for a scary, a bit gorey story, fearing a cheesy disappointment and I got honestly one of the most impressive ( spooky ) stories I've seen in an anime. My only gripe is that oh, it should have been longer!
The story really impressed me for the genre. It was clever, fresh and the telling of it was done really well. Very unpredictable too, which I lift my hat for since people tend to lean towards predictable scary stories. The atmospheres changed fluidly from ( slightly tense ) ease to thrilling and unnerving.
The artwork was beautiful and as an owner of ball-jointed dolls I really loved the detail of them as they appeared through out the series. I also loved the subtle creepiness of them, even considering their eventual role. Usually dolls are a pretty cheap gimmick to make a creepy atmosphere but they balanced their beauty very well. If one were so inclined you could speculate on their symbolism in the anime.
Also, the gore. There isn't a lot of it, but the gore there is is rather impressive. I like. Very nice attention to detail considering that it is a (non-movie) anime. Hooray for blood that doesn't look like ketchup ( Elfen Lied... ). This sort of thing rarely makes me go 'eugh' audibly but the first gore scene most definitely did.
Sounds... weren't particularly memorable. The OP was kind of interesting but not really something I cared to listen to. Not bad, but not incredibly good either.
Characters were alright, if a bit unbelievable at times ( honestly, they were quite relaxed most of the time considering their situation ).
At first I really didn't like the cover girl Mizaki Mei but once SPOILERS, I had to admit she suit her role and felt sympathetic for her.
The male protagonist Kouichi was somewhat uninspired, minus SPOILERS towards the end which left some questions in the air ( more in manga? ). However it didn't really take away from the series.
Overall I really enjoyed this show and I HOPE dearly that it gains enough popularity to inspire more proper horror anime.