As for the film itself, it is good.
Mel Gibson is not a great director, or a particularly gifted storyteller, but he has the Hollywood muscle and the money to pull excellent production managers and staff and they at least make his films highly polished. This film is no different. Except for one scene involving an animatronic/puppet cougar that looked kind of like the talking cat from Sabrina the Teenage Witch, the set design, props, makeup and costuming are extremely detailed. The camerawork is excellent; very dynamic and fluid with an emphasis on motion. Considering they shot on location in a tropical rainforest, this is nothing to sneeze at.
The visuals are plush and beautiful for the most part. Vibrant base colors (blue, green) are contrasted with rich earthy tones like brown and black and create a nicely textured visual composition.
The violence in the film is definitely over the top and gratuitous, in the same style as Braveheart. I am not particularly a fan of violence just for the sake of violence, but going into a Mel Gibson film you know what you are getting into. The violence in his films has this brutal, stylized Hollywood quality that I'm not too big on, but it is occasionally effective.
Shooting it in traditional Mayan vernacular was a nice touch, as was using totally unknown native actors. It's not just a novelty; using Latin or Aramaic or Yucatec lends the film another level of realism. What's the alternative? Having these guys dressed like Mayans and talking in English? Most films do go that route, and it creates some discontinuity within the film's world.
As for the story, there's not much of a plot, the characters are one dimensional and it's full of cheesy moments, but it's still fun. It is, at its core, an entertaining action chase film. But instead of car chases through the streets of San Fransisco, you've got a half naked man running through a forest being chased by a cougar in slow motion. You know what you are seeing is campy, but that is part of the fun. Like that scene in Braveheart where William Wallace is on top of a mountain with his sword and he starts screaming for no reason. It's a great moment. And you can be upset that Braveheart won all those Oscars because it certainly isn't Best Picture quality, but you can't blame the film for being what it is.
One thing: Gibson wanted to build the set for the Mayan city from scratch instead of using CGI, or miniatures. Bad decision. The wide shots of the Mayan city as underwhelming, given what would have been possible if he had opted for heavy CGI or miniatures. To be fair... they probably ate up most of the budget on costuming and makeup for the 700 extras.