A few things about this film struck me. My background coming into it is as an East Asian Studies major - I studied the language, culture, literature, film, history, religion, and politics of China. This was all done in undergrad so I am by no means the last word on the subject.
First of all, I noticed heavy use of Daoist symbols. The five elements were used - one per fight - fire, wind, water, wood, and metal. A message in the film seemed to show the Daoist idea that the harder you try, the worse you do, as Moon did in her fights. On the other hand, if you can go with the Dao (think: Use the force, Luke), you will succeed.
Second, I did not know before watching the film that it was Zhang Yimou's. His films are often critical of the Chinese Communist Party and sometimes have deep allegorical meaning. Some of his films are banned in China. Hero, on the other hand, seemed to be intensely nationalistic. Lately in China, the communist government has promoted nationalism (instead of populist Communist values as they did pre-1976) with a great degree of success. The use of the word "Tianxia" (literally "all under heaven," translated in the movie was "Our Land") seems Confucian and nationalistic at the same time. Although I would have not guessed this film was by Zhang Yimou from the plot or message, the cinematography was unmistakable. Hero eerily reminded me of another film, Yellow Earth (Huang Tudi), which Zhang Yimou did not direct but for which he did the cinematography.
Third, historically, Hero lacked in a few very obvious places. The Qin Emperor, Qin Shi Huang, was legendary for his fear of death and his Machiavellian rule. When his character states that he no longer fears death because of Broken Sword's words and invites Nameless to kill him, he is entirely breaking with the true historical figure of the emperor. Remember, this is the emperor who built an entire terracotta army to protect him from his enemies in death and spent a lot of money and effort looking for the secret to reach immortality. He was known for a Confucian philosophy spin-off known as Legalism, which is very similar to Western Machiavellianism. While his quick mind (or his advisor's) might have figured out Nameless's plot, he would never have hesitated in executing him.
Overall, this seems like a break from the usual genre one would expect from Zhang Yimou. I am not sure exactly what message he is trying to convey with this film, other than an endorsement of Chinese nationalism and perhaps Daoism as well.
