How bad is it? Terrible special effects and pure 1950's hokey sci-fi plot.
Should you see it? Definitely.
If you tried to imagine a low budget 1950's science fiction film, you'd come up with something very much like this film. It's a variation of Gulliver's Travels, an astronaut lands on a planet of tiny people and is shrunk so he can help them fight an attack by another alien race, the Solarites, which are among the most ridiculous monsters imaginable. The head Solarite is played by Richard Kiel, but other than his size, you'd never know who it was. An elderly Francis X. Bushman and Coleen Gray also star. There's an invisible force field, a mute girl who regains her speech when it's convenient to the plot and some of the worst rocket ship special effects foisted on an audience. Other than being slow in pace, this is a fun film to watch.