The story was pretty poor and full of poorly executed tropes, cliches, and other ridiculous shenanigans, which seemed pretty cheap and lame as they had a lot of potential since it wasn't based off of any sourcework. Definitely the worst point of the entire anime.
I /really/ enjoyed the art-work, but it suffered a few times during some fight scenes. The shading and coloring was beautiful, and the characters were really well defined visually.
Sound was just absolutely amazing, not just voice, but the entire OST and music that it had were great and very epic, which is sad since I wish everything else was as good as the amazing music.
Characters were full of cliches and only a few were actually interesting and original characters, and I admit among my favorites were Tsugumi and Hare, but I wasn't really that fond of Inori/Shu's character overall. Seemed very well, cliche as I said.
That being said, I fairly enjoyed the anime and it has some merit to being a fun ride despite the really poor execution. It had the opportunity to be something amazing and original but it ended up a generalized action mess, which really isn't so bad if you're into that and a lack of quality plot development.
