To start the review of this movie, one has to stress that it is based on a real story, a story so extraordinary that fits the "Truth is stranger than fiction" quote. In the dark years of Spain's post Civil War, in a poor and forgotten rural area, a small kid called Marcos was sold by his father to a shepherd, who taught him the basics of survival in nature, dying shortly later. Marcos became then a feral kid, establishing links with animals that still leave zoologists in astonishment.
A pack of wolves became his family. A snake he raised saved his life. And no: it is not a Pixar movie with cute "humanized" animals that speak and dance, they are real experiences.
Marcos remembers his childhood in the wild as the happiest period in his life, and his "rescue" by human society as confuse as humiliating.
Thankfuly, someone finally thought such a story deserved to be told as a movie. And unluckily, I wish it had been Spielberg who had done it, because despite of having the best of scripts already written by reality, it is only highly advised for people who love zoology and is interested in nature, as the situations in the movie are 100% real (furthermore: the director and scriptwriters found impossible to include the complete relationship of Marcos with the whole pack, his personal story with each one of the wolves, reducing it to his link with one wolf).
I am happy that the director has not fallen in easy Disney-like sentimentalism when picturing the life of Marcos in the wild. But in my opinion, considering the story, this movie could have been much better, it could have been breath-taking.