I was entertained. The theater was packed with pre-teens and teens (though mostly pre-teens). We went with 5 14 year olds and a 12 year old. They were entertained, though of course were bothered by some of the changes. These boys were uniformly disappointed with Eragon, but seemed to enjoy last night.
I had not read the books. I didn't have any issues with the satyr or centaur.
They did NOT spend much time on making the actors great swordspeople, by any stretch of the imagination. That was weak, I thought.
The CGI in the parthenon was excellent, or maybe just so overwhelming that I didn't notice any issues.
Entertaining, hardly deep or super great acting....