I've read some grumbles about the court scenes. These people betray their ignorance. This production went to simply amazing lengths to recreate all aspects of the period in which the story occurred. Courtly manners are something few people outside the court ever see. While the acting may appear highly stylized, it is, in fact, as close a replication as possible of the behavior of individuals in their particular stations as the director could create. The actor's facial expressions are a marvel, particularly the duplicitous Marquis Changxin and the King's mother.
There are, of course, reflections of both Greek and Shakespearian tragedy in the relationship between the king, his parents and his love. The juxtaposition of the king transforming from good to bad and the assassin from bad to good provides much food for thought on the evolution of an individual's nature. This movie would provide much to ponder in a college course on the humanities.
At the same time, it almost rushes along, even in the slowest scenes heading towards an inexorable denouement. One suspects the involvement of large portions of the troop movements, which were quite awesome. It makes The Lord of the Rings battle scenes pale by comparison. Few directors have the ability to literally field thousands of humans on the field of battle just for art's sake. I recall one scene in which at least 30,000 troops can be seen moving across a huge plain. The logistics for such a shot would have been staggering.
I could go on... but simply, I can't recommend this film highly enough.