As both a writer and reader of fantasy and medieval stories, this movie stands out to me not only for its originality of setting, but also it's cast and it's stunning visuals.
People can go on about how it is a westernised retelling of the 47 Ronin, and this makes it bad. My question to those people is, why is that a problem? Honour, duty and devotion to an ideal, creed or individual are attributes shared across all cultures around the world. This movie, to me, celebrates this fact, and thus has my praise.