A pleasant surprise. I didn't appreciate that many of the characters were so disposable since I found most of them likeable and relatable. Each of the character backstories were rushed but nicely done for a two-episode OVA. The story/premise was a bit cliché: It's your standard futuristic dystopian society with a socioeconomic class system and planetary level threat that results from genetic modifications to mankind. I think the action sequences for the cockroaches establish their strength and intelligence pretty well; the potential danger they pose to humanity at large comes across clearly. All things considered, I think 80% of the the show was fighting. If anAttack on Titan-Baki mix sounds like your cup of tea, you'll probably enjoy this.