Wasted Potential
It is tough to keep sequels fresh but the concept was excellent.
They broke the first rule of sequels is make sure all of the principal characters are played by the same actors. Now the son was going to be older but losing Rachel Weiss REALLY hurt. The chemistry was lost.
The terra cotta warriors and the Indiana Jones style of finding the emperor and his army worked. At that point everything else seemed formulaic. It is too bad they didn't go with something different to the series to find the way to beat the emperor. Once you get to the point where the Chinese army gets involved the movie becomes very mediocre.