What we have here is a rousing boy's adventure story, adapted from stories that Edgar Rice Burroughs cranked out for early pulp magazines. They lacked the visceral appeal of his Tarzan stories, which inspired an estimated 89 movies; amazingly, this is the first John Carter movie, but it is intended to foster a franchise and will probably succeed.
Roger EbertThe buried code of many American films has become: If I kill you, I have won and you have lost. The instinctive ethical code of traditional Hollywood, the code by which characters like James Stewart, John Wayne and Henry Fonda lived, has been lost.
Roger Ebert