"Dr. Cyclops" is known as one of the better "early sci-fi" films, made in '39 and released in 1940. (It is also in color.) But while the story has potential and there are some good moments, this is a very confused film.
The plot is simple - crazy mad scientist on some remote island can shrink animals, and wants to try it on humans. He manages this on a scientific team that came to check things out. They get angry, and the crazy scientist eventually gets really angry because his new shrunken subjects won't cooperate.
The thing is, the film doesn't seem to know if it wants to be a thriller, or a goofy movie. Dr. Cyclops (never called that but referenced to a Cyclops after one lens in his glasses breaks) looks cool in his "30's style sci-fi helmet" as he performs experiments and can be chilling at times. But there is so much "Disney-style goofy music" going on that it is hard to take anything seriously. The music belongs in a family comedy for the most part, and is played when the shrunken people do things like try to survive, and creep around the floor. Add that a few of them have pretty gruesome deaths and that just adds to the confusing atmosphere.
The FX aren't so bad but nothing special. The giant sets built are pretty impressive though. There is a scene where little fires are tossed at a real crocodile's head which probably made animal activists angry.
It also takes a long time for anything to really happen. This movie could have been done in a nice tight half-hour. Good for a viewing, but you probably won't watch again. The performance of the guy who plays Dr. Cyclops is definitely the main attraction.