The digitized animation is amazing and we saw it in 3-D which was also not wasted on this movie but I would definitely not recommend this for kids under 10. It is extremely suspenseful and even scary in some parts--certainly on the edge of you seat action.
We took 7 girls around the age of 10 for a birthday party and they all seemed to love it. Personally, I think it would be even a little better for boys. I didn't expect to enjoy it from the trailers but I did. Two of the girls were actually a little afraid in the fighing sequence. Overall It is a terrific movie, though.