While Umberto Lenzi began the Italian-made cycle of brutal Amazonian cannibal horrors with Il Paese del Sesso Selvaggio and effectively ended it with the nauseating Cannibal Ferox, it was Ruggero Deodato who directed the subgenre's most enduring film. This popular bloodbath features a fetus ripped from a woman's body, people impaled on spikes, a genuine tortoise-flaying, and numerous other indignities, both real and simulated. The plot concerns the efforts of a group of American explorers to discover the fate of a missing documentary film crew. They receive a scratchy film-reel containing the bloody truth from a tribe of tree-dwelling natives, and the reel's contents make up the bulk of the film. Advertisements claimed that "the crew who filmed it were actually devoured alive by cannibals," yet most of them were spotted alive in future unsavory gore films. While the film is undoubtedly gruesome enough to satisfy fans, its mixture of nauseating mondo animal slaughter, repulsive sexual violence, and pie-faced attempts at socially conscious moralizing make it rather distasteful morally as well. The fact that the film's sole spokesperson for the anti-exploitation perspective is played by porno star Richard Bolla should give an indication of where its sympathies lie.
~ Robert Firsching, All Movie Guide