From contemporary reviews, "The New York Times" called the film "an ear-splitting Japanese-made fantasy, photographed in runny color and dubbed English," and concluded: "This Metro release is crammed with routine footage of death rays and scrambling civilians, not one of whom can act." "Variety" called it "well-produced", noting "special effects involving sliding land, quaking earth and melting mortars are realistically accomplished proving the facility with the Japanese filmmakers deal in miniatures." but found the film "As corny as it is furious" noting that "While Junior may be moved by the arrival of outer-space gremlins, big brother and all like him will laugh their heads off." The review commented on the English dub, stating that it was "understandable enough, but one might easily believe something was lost in translation." Harrison's Reports wrote that the film is "far better than most American-made pictures of its type" and ""although the story idea offers little that is novel, the action holds one's interest well mainly because of the imaginative settings, the elaborate space ship used by the invaders along with its many electronic gadgets, and the very good special effects by which catastrophic scenes of destruction are depicted while the invaders and the Earthians battle each other all sorts of weapons."