This movie received mixed reviews, many complained that Mel Gibson had used to much violence.
I think this is an awesome movie and that the level of violence is quite low. The level of realism is quite high. One should not misunderstand high level realism with unnecessary violence.
I have absolutely now idea what the Mayan used to wear but I have to say all the effects, makeup and clothes are extremely well done. It seems to be totally authentic. In this case "seems to be" is sufficient for me.
The movie does not follow a traditionally story line and neither is it an epic movie. It is more in the special theme genre, and I think the theme this time is the not too unknown: Survival. This keeps the movie on a constant edge. Still Mel Gibson has not gone in the trap of making it a fast pulsating movie but instead he gives the movie air during each thrilling moment - which in turn increases the thrill and the watchers joy.
To say something bad about this movie: It seems that it they are using some kind of high end movie equipment which sometimes when there is to much going on - gives to much realism which in turns seem unnatural. (I saw this in last years Miami Vice as well) - I think maybe this is somewhat correlated to Walt Disneys problem with animations where too realistic movements lead the animations becoming funny. It is not too often this happens tough and most people will probably not even notice it.
All in all: a really enjoyable movie.