Continuity mistake: At the beginning of the scene where the pilot's wife is attacked in her bedroom by (not) Bela Lugosi, look at the pictures on the wall above the bed. After the attack begins, the pictures are different.
Continuity mistake: After the villain (Thayer David) kills a duck, a boulder begins to move and brushes the side of his right leg as seen in a close-up and both legs can squarely be seen as he is standing beside the rock. The scene changes to a stunt-man who has his left-side towards the camera and this time his right leg is closer to the boulder which pushes him over a ledge. (01:50:35)
Continuity mistake: In the part when the two American officers are looking around in Anchorage, USA, and come across the dead woman at the News Studios you can clearly see her blink 2 or 3 times as the camera pans out.
Continuity mistake: When the MR-1 first lands on Mars, the sky visible through the portholes is fiery red, which is the uniform color of all exterior shots in the film. However, a whole series of interior shots throughout the film show that the sky visible through the portholes is suddenly and inexplicably baby blue. At two points, when Iris sees a Martian through the porthole, the sky momentarily turns pitch black.