Going into this series without expectations is a good thing, since it manages to shatter just about everything you could expect from a series like this.
The most notable thing is the art style, which is reminiscent of Gankutsuou
but possibly even trippier. Besides just being a visual gimmick it's also a story telling device, and rewatching episodes will often reveal things in the background that are subtle foreshadowing or hints of things to come. Since the series is primarily a horror story things will often jump out and scare the crap out of you, and the art style helps enhance this and increase feelings of unease.
You could theoretically watch the series out of order, since each arc is self contained, and besides the Medicine Seller there are no recurring characters. Nonetheless the focus characters of each arc have interesting backstories that we only gradually dig into, and more often than not what initially seems unimportant turns out to be vital to the story and what's really going on.
I'd highly recommend this series, simply because you'll never see anything like this ever again.