What really first struck me was the character design: I came across the image (above) back in the day when I had the time and luxury to browse around the net, aimlessly looking for nice pictures. Think of it as creepy or however way you like it, but I thought that the lock on the female was a pretty interesting concept for an anime. At that point, I obviously didn't know what anime it belonged to, and promptly afterwards endeavoured to find out.
Whilst the plot was relatively interesting and appealing, it's definitely an anime which was not exactly the type you'd generally find me watching. Not only was there no romance, but overall, the anime emulated and implied a much darker and supernatural tone. I guess you could categorise it under the "Thriller" genre.
Anyways, after finally coming around to watching it, I can conclude that whilst different from what I'd generally consider watching, it was enjoyable. I do feel that the producers, rushed through with the plot and squeezed as many events as they could into 12 episodes resulting in an episodic situation that would've often confused even the most attentive of viewers (myself included). Despite these short-comings, if I was to consider each episode in isolation, they were individually quite interesting and enjoyable to watch. I liked the mysteries that they presented, and I enjoyed how they came to resolve each respective 'mystery' that arose in each respective episode. The setting was also quite a nice change (post World War I, England) and well replicated.