Steve Reeves clone Richard Harrison stars in the sword 'n' sandal Giants of Rome. The Eternal City is threatened by a modernistic doomsday weapon. Harrison decides to investigate, cutting a swath through various well-armed antagonists. It turns out that the horrible weapon turns out to be little more than an outsized catapult. There was a huge built-in audience for this sort of fare back in 1964, so it hardly matters whether or not Giants of Rome is any good...though it is better than most of its kind.
~ Hal Erickson, All Movie Guide