This movie is better known as Medusa Against The Son of Hercules.
Submitted to the British Board of Film Censors as Perseus Against the Monsters by Miracle Films. Passed with an "A" certificate on 27 February 1964, the censors obviously having concerns that the monsters would be too scary for unaccompanied children. One of the few Italian epics to enjoy a West End run, Perseus opened at the Gala Royal on 26 March 1964, accompanied by The Tiger of Eschnapur (1959), and ran for two weeks. Also unusually, the film was reviewed in The Times on 2 April 1964.