Despite the theme as explained by others, I found this series difficult to watch. The pacing is extremely slow, monotonous and boring. The people are dull, gloomy and unhappy. I'd hate to live among their frigid lifestyles. Nobody has a sense of humor and they're miserable.
The fact the dead are coming to life is largely ignored by the community.
There are no likeable characters so eventually I didn't really care on the progression of the storyline.
The gloomy story bored me intensely.