This was the little direct-to-video that almost roared. Almost that is, until people got their hands on it and watched. Then the nascent roar turned into a resounding "meh."
The plot is so outlandish that the resulting movie had to be either insanely great, or just insane: a small cadre of Nazis escape to the moon in flying saucers in 1945. Hidden on the dark side (a fitting place, given their ideology and helmet shape), they build a base, a new society, and eventually an Earth invasion fleet. Their dastardly plans (can movie Nazis have any other kind?) are interrupted by an American moon mission circa 2017. Interrupted yes, but also boosted decades ahead by some seemingly innocuous technology salvaged from a captured astronaut.
With such a whacky idea, it could either be played deadpan straight or for Mel Brooks style humor. The producers chose the latter, which is probably the better choice, but they couldn't quite pull it off. At times it's pretty darned funny, but the bulk of the jokes fall flat. It is jaw-dropping upon occasion, either for the spectacular bizarreness of things like a well-rendered Nazi moon base, or for yet another lame race joke. It starts with more of the former and shifts to more of the latter as the movie progresses, and finally runs out of steam entirely by the end.
Bottom line is that it gets 1.5/4 stars. Drinking heavily while watching with a raucous bunch of friends may boost this by as much as 1 star, but only if they're well attuned to Mel Brooks' brand of humor and aren't too offended by amateurish efforts to replicate it.