Googlevideo has it online:
The New York Times says it "is a faithful and disarmingly earnest attempt to honor some venerable and popular Chinese cinematic traditions." Slant Magazine calls it a "family-friendly fusion of The Lord of the Rings, Crouching Tiger, Hidden Dragon, and The Karate Kid". The Guardian calls it "a close thematic relative" of The Karate Kid. Salon.com calls it a "love letter to the conventions of martial-arts movies" and says it "is so good-natured, it's easy enough to disregard many of its flaws." Moria doesn't like it. Locus Magazine has a review. Variety has a mixed review, closing with this:
On the upside, "The Forbidden Kingdom" is brisk and colorfully realized, with excellent contribs not only from Pau's handsome widescreen lensing and the impressive Mainland sites deployed but also from Bill Brzeski's splendid production design and Shirley Chan's costumes.