Well I think this will be my shortest review (normal, it's just an "ova"), so let's get to the point.
I like Kagerou Project, I don't know if I could consider myself a "fan", but I really like it, the thing is that, despite that, it really hurt to see this ova (I will talk all the time, not like in the other reviews where I separate and analyze more deeply aspects of the ova).
First; the redesign of the characters is good, I could say that it is a way to mark distance from the original anime (Mekakucity Actors) and thus attract more attention, the colors are still distinguishable in the characters (not as much as in the original anime), but beyond that all good, does not change the essence of the character at all.
The point that falls most on this ova is the fact that; it is unnecessary and it makes no sense (or simply the events generate almost nothing of the plot's development), this is noticeable because they use the fact earlier in the plot to introduce more drama to a scene that, in the original series, It lasts 1 chapter and that is also set aside, so it can be deduced from the first moment that the events are irrelevant and just want to give more "flavor" to a normal moment in the anime.
Also the introduction is very abrupt and the animation does not accompany at all, in fact at the beginning the animation is quite clumsy when it tries to "play" to add more emotion or fluidity to the intrusion of terrorists in the mall, the animation also It falters throughout the ova, there was no great effort in truth (a special mention to the fact that apparently the Seiyus had a bad day, that would explain their demotivation and little effort to double the characters, also the fact that in some scenes the character's voice is heard, but his mouth does not move).
They tried to divide the prominence across the entire ova, resulting in a lot of nonsense throughout the ova, silly and illogical actions (such as when Seto and Hibiya try to save Hiyori), making the ova look much more silly than what in principle could be (oh and, as is the terrorist attack, the scenarios are very muted, all the scenarios seem the same and that makes it very boring, obviously the colors too).
The enemy seemed to have red eyes just like the protagonists, which in itself makes no sense, in the original plot makes it clear that there are only 10 snakes and breaks all logic and credibility the fact that a character appears with another snake.
The final scene was interesting, the fact that it is understood that the characters die in the explosion at the end complements the revelation of the reboot of the universe in the original series, at least there they made a good move.
Well, I said it was going to be short and so it was, I think it is clear my discontent in all aspects, thankfully I can still enjoy the other material, but without a doubt this is the worst related to Kagerou Project, if you want to complement or add something to the original anime, at least do it right, and if you don't intend to do it right (which is what I believe after seeing this ova) then do nothing, please