Watched the entire series in about 3 hours ( had to stop and work on some stuff for a while).
The imagery was very well done. The story could easily be expanded, but then it runs the risk of becoming something that would drag on, or be destroyed by bad writing.
The show did get confusing at times, and there where a few unfinished plot points that would have helped to expand the show into a fuller 7-8 episodes. The antagonism between Ayane and Tohru, feels tacked on after the initial fight, and has no closure. by the end of the series
I felt when watching the last few moments during the mental battle between Tohru and Leviathon, that there was a lot of reference if not outright mimicry of Neon Genesis, not a bad thing but noticeable, how the scenes played out felt right in how they were done, presented in such a way as to help see what kind of "monster" Tohru was fighting against.
Overall good show, definitely worth another watch, to catch anything missed.