If I want to do an explanation for my opinions on Kagerou Project's anime adaptation, first, I'll have to start with something basic. Where did this enthusiastic and interesting story come from? I'll make this quick and short as many of you should already be familiarised with its origins.
Kagerou Project is a series of Vocaloid songs made by the Japanese creator Jin that tells a story inside each one of them from the point of view of different characters of its cast and different endings or "routes", sometimes getting those mixed in the same song too through parallelism (for the case of "Lost Time Memory"). Later on, the story that these songs tell us got translated into a series of light novels that explained the situation even better and let us understand better what was going on, as well as filling up blank gaps.
The story that was told was one really resemblant to the anime's story. A story that was original and unique, that presented us with a really deep philosophy about life in itself and different ways to face it, even if this story mostly ended in the continuation of a cycle in which the protagonists have been trapped in.
And now, when it came to the anime, one could agree that their original plan would be a really successful one, with Akiyuki Shinbou, as well as the rest of Shaft's staff, taking part developing it. However, we ended up with beautiful visuals (as expected from Shaft) but with an unorganized way of telling the original story. This bad organization can be understood when seeing the anime for the first time with or without knowledge of the songs. This series ended up in 1 season and 12 episodes, in which they had to divide 7 volumes of the novel (or, at least, those who told only one route), so it isn't too hard to understand how the anime can be so difficult to understand for newcomers to the series.
But, if I had to defend this anime, I would say that "it is suitable for those with, at least, the minimum knowledge about the project and the series". Its visuals are truly what one could expect from an anime from Shaft and they suit the Kagerou Project perfectly, as well as telling us a route with a new ending to it in which everyone can continue their lives in peace. The soundtrack (setting the Vocaloid songs, now sung by real Japanese singers, aside) is beautiful and calming and, all in all, it could have been an excellent anime.
So, concluding this review, I have to say that even if I was disappointed with the anime's outcome, it wasn't completely bad for me. Perhaps for being a Kagerou Project's fan or for just being an anime fan in general, while this anime could have really ended up infinitely worse because of the story's complexity, that luckily wasn't the case. As a last warning, I recommend that, before watching this anime, you listen to Jin's songs, as they can all be found on YouTube (either sung by IA or in the format of covers).