For many years this early science-fiction film from Italy was thought to be lost. Some reels of the Portuguese release version were discovered in Brazil. This amounted to 740 meters, which is believed to be approximately 40% of the complete film. Luckily, the discovered footage came from the later part of the film and included some of the special effects and the battle of the two robots in the Opera House. As of mid-2006 this is the only footage known to survive.