While there is lots of wuxia action in the movie, it is actually about star-crossed lovers. The title refers to a martial arts manual that plays a very minor role in the story, and the opening scene (a great combat on a lake) is a bit misleading as to what follows.
I liked the way history was told from a different perspective: a focus on the marginalisation of Korea during the Yuan Dynasty, when they were mistrusted and ill-treated by both the Mongols in the North and the Han Chinese in the South.
I’m really not familiar with Korean movies, but I do know that the leads have a nasty tendency to die. By contrast in Chinese movies, everyone dies at the end.
The story felt like it could have been longer, and I have to complain at how the main characters would go to their deaths rather than raise their son…