you really can't compare this movie to the rest because each one is so different from another that the series is really just three different movies, not a trilogy.

The action is nicely done, though Sam Hui isn't as graceful as Jet Li. He can't do splits or flips(not very well,anyway). I liked this one better than two overall because the more dominant role of the Ming government than in II where the gov. soldiers disappeared in the second half of the film. This movie is about corruption and the evils it brings. The "Sacred Scroll" is just said to give one supernatural powers. You don't need to know exactly what, but everyone wants it.

For those that have seen part 2 and haven't seen part one,
There are LOTS of inconsistencies between these two.
First, Kiddo, has no crush on Ling. In this film, she disguises herself as a boy in the first half. Ling isn't in love with Ying at all, if anything, he likes Blue Phoenix.
The Sacred Scroll is from the emperor's library, I guess in part 2 the goverment stopped caring about retrieving the scroll that would teach supernatural power.
Kiddo's father is the Wah students' corrupt teacher.
As to where Asia the Invincible came from, I don't know. In the end one man steals the scroll, but he isn't related to the Sun Moon Sect at all.
Part one also has the origin of the "Hero of Heroes" song.