Most of all, what I truly respected in this series was its character-driven action, as opposed to plot-driven action. The characters were so fleshed out and their relationships and backgrounds so completely delved into, I had grown to feel like they were real people I knew. This was further effective in the juxtaposition that was utilized between future and present selves of these characters (which I will refrain from spoiling further about). The development of relationships between and of the numerous characters in this series, Yuu most of all, was unimaginably compelling and convincing, giving the series an overall true feeling of completion and purpose.
Haruka, most of all, pulled me into the series more and more with the further displays of her distinctive features. Having the ferocity and absolute concern of Hermione from Harry Potter, and the curiosity and strength of Lyra of The Golden Compass, the pleasant down-to-earth character of Haruka was one that you would simply be honored to be friends with. Despite her rough upbringing, her inner strength and selflessness were clear and well-presented in a realistic manner. Yuu, too, was a realistic character suffering from a harsh upbringing and from the effects of strained familial relationships. The relationship found between Yuu and Haruka, and their development, is what I truly believe to be the defining point of this series.
The story, too, gives this series what I believe its distinctness and genius. Carrying across a story filled with Quantum Mechanics, and a great deal of everyday storytelling in a little town in this mix, I believe that the timespaces and parallel universes shown in this series to be an absolutely interesting and entertaining interpretation of Quantum Physics and many of its theories. The unique settings and conflicts only help to improve upon this story.
The only problem I had with the story was the sometimes slow pace of it in the middle of the series. Whereas a lot of information and details given were important, I believed that if I wasn't motivated enough to finish the series, I might have stopped just because of that slowness.
In terms of art and sound, I believe that Noein also delivers. The art was particularly special (even though there were some parts I believe the CGI to be sort of distracting) with its mix of CGI and line art, and the classical music used was clearly appropriate.
Overall, this was one of the most enjoyable, if not the most, anime series I've ever watched. If given the opportunity to watch this series, I suggest and strongly recommend to not let it pass.
