The characters and story feel very human - people have issues and try to deal with it, people die, people are left behind, etc. Even through there are monsters that eat people, the characters and story felt believable within that world. The artwork really drew me in as well - the drawing is good, but more than anything the use of very subdued colors and earthtones conveyed a sense of their world.
Also, there's no filler and each arc of the story is very well written.
