Playing almost like a Roman-era version of THE GUNS OF NAVARONE (1961) with an elite group of specially-skilled soldiers handpicked by Julius Caesar to go on a suicide mission and destroy the Druids' secret weapon this is an agreeable time waster which is moved along at a brisk and efficient pace by prolific director Margheriti. He was perhaps the most erratic of the three Italian genre specialists (the others being, obviously, Riccardo Freda and Mario Bava) who basically set the foundation of what today is referred to as "Euro-Cult"; I've now watched some 9 of his films and the most satisfying have been his 2 horror outings starring Barbara Steele THE LONG HAIR OF DEATH (1964) and CASTLE OF BLOOD (1964).
Sensibly, THE GIANTS OF ROME does not opt to make its heroes invincible (as was usually the case in films of this type) and despite a happy ending, all but one member of the group lose their life in accomplishing the all-important mission. The "secret weapon", however, turns out to be a major let-down: though one of the Romans expresses great surprise at never having seen anything like it, a little while later the leader of the group refers to it by name as if he had been around such devices all his life! Still, the most hilarious moment of the film came when the leading lady solemnly tells our hero her life-story which includes the fate of her father, one Fulvius Lucisanus (Fulvio Lucisano being a leading Italian producer of the time, though he doesn't seem to have had anything to do with this particular title!!)