Shame the Nazi angle was sacrificed for the commie threat
Imagine the impact of the film today if Hitler - Hitler! - is revealed to be behind the germ warfare plot and is still alive in Winnoga! Wow, that would be outrageous - but would make complete sense when you consider the mad doctor Bucholtz and the human experiments the Nazis undertook. Somehow it just doesn't work with the villains being ex-Nazis who have undergone a 180 degree political realignment and are now commies.
The acting in the film was questionable but I liked the direction. Some of the shot compositions were effective. One memorable shot showed Corbin, Janet and Dr Keller all reflected in a mirror. You could see that attention was paid to the mise-en-scene and where characters were located in the frame.