Despite being only 13 episodes, the series definitely tries to give plenty of feels, especially in the latter half. There are also some OK battle-scenes, although they tend to be short. This is definitely "seinen" grade - younger viewers might not enjoy some of the more mature themes explored. Some other reviewers pointed out that there is a "loli" aspect. While there's a nod in that general direction, this also ties in with the story, although as far as I know, there's no explanation why that particular class of person [spoilers redacted] cannot be male.
Is this anime worth watching? I believe so. Black bullet is not a top 10 series by any means, but very enjoyable nonetheless, and at 13 episodes, why not?
