The art is super inconsistent. The show has flashes of beauty, but those moments are few and far between, and for every one truly beautiful moment there are a dozen ugly cringe-worthy ones. The way characters are animated is really inconsistent as well. Sometimes they'll be super tall and thin. Other times they're overweight and oddly shaped. The inconsistencies with the art are really noticeable and absolutely detract from the show. Often times the show looks older than it is, which is rarely a good thing.
The voice acting is below average. There are zero standout performances in a positive way, though the two best, keeping in mind that best merely means passable, in the dub belong to secondary characters Toby and Koriyama respectively. The voice of Atori is over the top and impossible to take remotely seriously and the voice of Uchida is absolutely terrible. The actress can't decide where her accent is from. Sometimes she's from the southern part of the USA and other times she's British even though her last name is very Japanese.
The character development is PUTRID. These are among the most shallow, undeveloped, one dimensional, cookie cutter characters you'll ever see. Basically every single character has one role or purpose in the bigger picture story and that is the long and short of who they are as a person. The anime also wastes entire episodes on characters that are completely unimportant to the story, such as Yuu's mother, which only exasperates the anime's clear pacing issues and multiple slow, dull stretches.
Karasu is repetitive and has a five line vocabulary. He's like one of those toy dolls with a string where you pull it and it says one of five possible lines. From him you get Protect Haruka, Save Haruka, Haruka is in danger, I love Haruka and Haruka. He's not the only one though- the writing as a whole is really basic and crappy. It could have been written by a middle school student. Cheesy, bare bones lines are everywhere in this anime.
The music during fight scenes was actually really epic and badass. It was too good for the rest of the show, honestly. I tip my cap to the composer and only wish their work had a better anime around it.
All things considered, while this wasn't the worst anime I've ever seen in my life, objectively this show is just bad. I'll not be watching it a second time any time remotely soon and I honestly cannot recommend you watch it at all. It's just not good enough in any way to be worthy of your time.
+Epic fight scene music
+Cool, original premise (completely wasted by horribly botched execution)
+Semi-realistic/believable scientific concepts
-Inconsistent art/animation
-Some of the most underdeveloped, shallow characters ever
-Terrible writing
-Below average voice acting
-Pacing issues/dull stretches
OBJECTIVE RATING- 4
PERSONAL ENJOYMENT RATING- 4
