Story: Redefining time-travel stories. This anime (imo) is better than the Back to the future trilogy and suspensive as Death Note or Code Geass. The characters action, reactions, thoughts are realistic (well, realistic for a sci-fi, as D.N. is realistic for a fiction). The story starts a bit slow-paced but as it proceeding to the conclusion it's getting even more deep, suspensive, romantic (especcially in its original meaning (originally it was like an escape from the darkness of reality)) and complicated. The big thing about it's complexity is the way it's remaining understandable even when the timelines and thoughts are totally relative. In addition, the narration is superb awesome.
Anims: Well, it's not epic as a CGI movie but realistic and beautiful, especcially the light-dark contrasts and the focusing. It's greatness the same as any animations, books, comics, etc. :it highlights the important things and leaves everything else to your fantasy. (if you don't understand, check out Scott Mccloud's comics/books about comics)
Sound: The opening is one of the bests I've ever heard, the ending is great too, but a bit too slow for me. Anyway, all the sounds, effects, voices, songs are perfect and perfectly timed.
Characters: Everyone is complicated (well, more complicated than in Soul Eater but not that original/funny) and independent. The best thing is that they are acting realistic.
overall: Must see, I don't want to tell more because every moment of it is great and if I would spoil them I would hate myself.
oh, and don't be freightened by it's lackness of visual action, it has a much more better story than most action movie/anime/etc.<div id="-chrome-auto-translate-plugin-dialog" style="opacity: 1 !important; background-image: initial !important; background-attachment: initial !important; background-origin: initial !important; background-clip: initial !important; background-color: transparent !important; position: absolute !important; top: 0px; left: 0px; overflow-x: visible !important; overflow-y: visible !important; z-index: 999999 !important; text-align: left !important; display: none; background-position: initial initial !important; background-repeat: initial initial !important; padding: 0px !important; margin: 0px !important;"> <div style="max-width: 300px !important; color: #fafafa !important; opacity: 0.8 !important; border-color: #000000 !important; border-width: 0px !important; -webkit-border-radius: 10px !important; background-color: #363636 !important; font-size: 16px !important; padding: 8px !important; overflow: visible !important; background-image: -webkit-gradient(linear, left top, right bottom, color-stop(0%, #000), color-stop(50%, #363636), color-stop(100%, #000)); z-index: 999999 !important; text-align: left !important;"> </div> </div>