In a casual sense, "The Hills Have Eyes" does some very plausible, I can understand someone believing it in part or in whole, easily. But from a scientific standpoint, the film suffers from so many issues that it becomes pretty obviously fake. First off, the radioactive mutants are, although interesting, nearly impossible. You see, radiation can't quite mutate your entire body, but rather specific cells. Although it is possible for every cell in your body to undergo mutation, the vast majority will simply die, meaning you will, too. An unborn child could potentially become a mutant if the stem cells it was recieving were undergoing cell mutation, but the chances of it getting its vital organs intact is nearly impossible. And then there's the issue of cannibalism. Now, we've already debated that in order for the mutants to even exist, they'd need to undergo severe mutation at a fetus stage, and yet still retain working heart, lungs, brains, and digestive systems. But for them to suffer any form of insanity, or cannibalistic tendencies? They would need to have impaired brain cells in the judgement and common sense governing areas of the brain. But, that would affect their ability to eat, breathe, or survive in general. In order for the right cells to be tampered, that would require the kind of surgical precision A-Bomb fallout just can't provide.