For speaking Spanish, a great effort, and a good performance. He is a very versatile actor. I, too, thought that the creepy factor of the movie was going to rest on the child and her situation but I found that the fear was instilled by putting these men in a foreign town and in a situation out of control.
The movie opens with a song about "war" and I think this feeling predominated in the movie. I also found creepy the transformation of the more docile character (Paul's friend)
I also found that although the movie repeated some stereotypes from other scary movies, it was done in a sober manner. The performances (of the men specially) were good and credible. Maybe we were expecting a more "chilling" movie, but I took it for what it seems to be: a war among men, natives and foreigners, the primal versus a more civilized attitude but at the end: all primal.