I can see that certain viewers were deeply disappointed by the lack of horror in this movie. I was a bit surprised, too, considering that it belongs tot the 'Peliculas para no dormir' series. Still, I don't think this is a flaw itself, as I don't think it was intended to be a horror, despite the title of the series, or at least not a classical one.
I found it well directed and the actors doing a good enough job to make the story believable and the viewer curious. For me, the small amount of what is called horror was enough to picture the mental torment of Tomas, and to keep the story realistic, without useless elements that usual only ruin the logic of the movie. It was obvious that all the 'surreal' elements were only visions of Tomas, who was slowly losing control under the pressure of his own past and his deep remorse.
All in all, I think it's worth watching this movie and that its rating is way too low. This proves again how misleading ratings can sometimes be.
