As a girl, the overdone harem vibe didn't do much for me and there were times in the beginning that I found Chaika annoying. The characters are not particularly deep, they are a bit like stereotypes, and some episodes seem to have no point or impact on the story. Despite all that, by the end I was reluctantly impressed.
The world-building was admirably done. It's taken the stereotype of a fantasy kingdom and inverted it. The princess carries a coffin and causes trouble, the unicorns are wild and dangerous beasts, and the system of magic is - like our modern fossil fuels - based on powering the present with the remains of the dead. I also found it interesting that they've done away with the stereotype of all the regular people desiring peace and prosperity at any cost - these peasants desire war in a plausible and human way.
The princess's story arc is also remarkable. It's not the stereotype of an ordinary girl finding out she has a great destiny and learning to accept that responsibility, fight, and eventually rule. From the beginning there is no question that the princess has a special destiny. The question is whether it's a noble destiny, or a mission ordained by the devil. How will Chaika interpret her destiny, and what consequences will her actions have? because they may not all be positive. Like an dark alternative "Scrapped Princess" intended for a male audience we wonder about the princess's destiny. Is it to destroy the world or save it? But somehow the question of the ultimate outcome of the heroes' journey takes a back seat to the question "What do they, what does the princess, intend to do?" The hero in particular has no noble intentions, he acts nobly because he has a soft heart and a savior complex.
Would I recommend this anime to others? Sure. Do I think it's necessary or interesting to watch every episode? Not really, no.
