If you're in the mood for a classic Republic serial, this is probably the one to see. All the iconic elements are in place, and there actually seems to be some sort of energy put into the production.
However, the thing about these old serials is that they invariably lose a little something when taken out of their original context -- one episode a week, shown to kids at a matinee before the main feature film. Sitting through every single episode consecutively gets mind-numbing very quickly, and not just because of the fact that as much as a third of the footage is dedicated to updating the story from previous episodes. There's also the fact that, in order to crank them out quickly, the filmmakers stuck to the same formula for every episode. They're practically the same scenes, with only slightly different dialogue. Without so much repetition, the nearly three-hour running time could easily be condensed into a tighter, sub-feature length film. (In fact, most of them were cut down this way for later TV broadcasts, and some of those versions are still available on video.)
But still, the serials churned out by the Republic Studios assembly line (mostly directed by Fred C. Bannon and written by Ronald Davidson) have their own special charm -- the rocket ships equipped with office furniture, the hero's silly flying costume, the lone alien hiring a couple two-bit thugs to help him take over the Earth. They can be hilarious... in small doses.
The plot for this one? Does it matter? (Just for the record, though, there are no zombies in this serial. Nor does anyone come from the stratosphere. The bad guys are actually aliens from Mars.)
Thug: "You mean you can build a machine to rob a bank?"
Martian leader: "That's what it amounts to. Although you would call it a robot."
One of the Martian underlings, who is barely around long enough to even warrant a screen credit here, is a young Leonard Nimoy.
"King of the Rocket Men" (1949) and "Radar Men From the Moon" (1952).
Take a Look:
The trailer tells you all you need to know...