How bad is it? Numerous things associated with bad films have been named for this film.
Should you see it? 50 Million reviews can't be wrong. (Yes.)
This is the last mention of Larry Buchanan who's been on this blog a lot - Zontar is his remake of the film "It Conquered the World." John Agar fights a scientist who's ruled by a giant bat. There are mind control devices placed on people's necks. There's a laser gun that turns the film negative (such an obvious cheap effect, I'm surprised no one else has used it). It's endlessly silly.