Personally, I've always defended Santo films as an important part in the history of Mexican cinema, specially the ones that belong to the fantastic genres (fantasy, horror and science-fiction), as they were an influential series among the few movies of the genre done in Mexico. Sadly, I must say that "Santo el Enmascarado y Blue Demon Contra Los Monstruos" is not one of the best Santo movies, and while it certainly packs some fun and is an important step in the progression of the series (from horror to sci-fi), it also marks the downfall of one of the greatest Mexican directors, Gilberto Martínez Solares.
In the film, Santo and Blue Demon (played by themselves) are rivals on the ring, and partners in their fight against evil. One day they receive the news that Otto Halder (Jorge Rado), the famous scientist, has died. This wouldn't be weird, if it weren't for the fact that Santo and Blue Demon had suspected that Halder was a criminal mastermind. The fact that Santo's girlfriend Gloria (Hedi Blue) is Otto's niece made Otto a personal enemy of the duo. Santo has the feeling that Otto's death is not normal, but Blue convinces Santo to go on vacation while he does the investigations. As Santo had thought, Otto Halder is still alive, and after capturing Blue Demon and bringing back to life the mythological monsters of old, he prepares his revenge against Gloria, her father, and Santo.
While the story was written by Rafael García Travesí (who had written Santo's best and most famous films), the screenplay was really the brainchild of producer Jesus Sotomayor, a Mexican producer notorious for his excessively ambitious movies that while based on popular trends often showed poor results. Sotomayor's involvement in the writing of the story is probably the reason of the convoluted and hugely nonsensical plot, as the inclusion of numerous enemies (Halder himself, a vampire, a mummy, a wolf man, Frankenstein's creature, a cyclops, Blue Demon's evil clone, Halder's hunchback sidekick and his zombie henchmen) makes the film an absurd exercise in excess that ultimately destroys what could had been another good Santo film. García Travesí may not had been a terrific writer, but he knew very well how to mix monsters with Santo's trademark action, and in this film the whole formula gets overused to the point that it becomes surreal.
While the atrocious excess in the plot is awful, I think the real tragedy of the film is that it shows how low the career of director Gilberto Martínez Solares was at that point. From being one of the most important figures in the Golden Age of Mexican cinema (directing the best films of genius comedian Germán Valdés "Tin Tán"), he witnessed the downfall of the Golden Age and like many others, worked on sub-par productions in the darkest years of Mexican film industry. By the early 70s, old school comedy films were not popular, so he started directing adventure and sci-fi films (the first being "Blue Demon contra las Invasoras" in 1969) and later sleazy and zany low-rate comedies through the late 70s and early 80s. While a very effective director in comedy, Martínez Solares showed an very anachronistic vision when he started making sci-fi films, and this film demonstrates it.
The film has a very 50s look and if it weren't in color it could pass as a film straight from that era, as the camera-work and the overall style of the film look dated (even for the 70s). The low-budget of the film doesn't help with this as most of the make-up and special effects (like the Cyclops costume) are incredibly cheap. However, not everything is bad in the film, and it could be said that this film (along with the previously mentioned "Blue Demon contra las Invasoras") started the new evolution of the wrestlers sub-genre, moving away from the Bond-like style of films Santo was doing at the moment and taking him back to the fantasy realm in sci-fi adventures of mad doctors and kitsch futuristic designs.
Depsite all the flaws, Santo's charm works and he delivers a fine performance with the little he had to work. While it looks like Santo feels awkward working in the film, he gets the job done like only he knows how to do. Blue Demon seems to have more fun, and he has the meatiest role, as after he is captured he is cloned and the evil clone is sent to kill Santo. Jorge Rado as Otto Halder delivers a good performance, although the script doesn't really give him a lot to work with. Hedi Blue was not really a talented actress and her short career shows that she was only in the film for her good looking face.
While overall this Santo film is disappointing, it's fun to watch in group, as the absurd plot and excessive amount of badly done monsters can make for a fun night at the movies. It's a shame that the careers of Santo, Blue Demon and Gilberto Martínez Solares were involved in this film, but at least this opened new grounds for Santo and other wrestlers. Sadly, it also meant the beginning of the darkest hour for Mexican cinema.
Review by José Luis Rivera Mendoza from the Internet Movie Database.