Black Bullet is the Dengeki Bunko equivalent of Attack on Titan, complete with giant walls built to keep colossal regenerating enemies out, gratuitous violence, and internal power struggles. However, there are some differences. For one, the story is set in the near future, and revolves around more modernized weaponry such as guns with bullets made out of a rare black metal (Hence the title, "Black Bullet"), private companies commonly referred to as CivSecs (Civilian Security Agencies) that more resemble if the Men in Black were all private mercenaries, and the fact that certain characters are essentially overpowered cyborgs.
That being said, the story is actually really good, despite the show's thirteen episode run. It was pretty decent. Not fantastic, but it was certainly better than a bland show such as The Irregular at Magic High School. The ending however, well...it was kind of weak in my opinion. I honestly preferred the ending of the fourth episode more than i did the thirteenth, but I guess that's why 13 is considered an unlucky number.
In summary, Black Bullet was a halfway good show with great ideas right up until it's somewhat weak ending, in my opinion.
