The special effects are awful. The "monster" looks like a puppet from a television show for little children. And the documentary-style narration is laughable. But, it has some redeeming qualities as well.

One of the main characters is a female mathematician who is collecting data from test flights and develops a romantic relationship with the one pilot who survived his encounter with the monster. In 1957, portraying a woman as a competent mathematician who contributes to solving the problem rather than simply being a "damsel in distress" was a rare and notable achievement. In addition, I am pleased to add that she is not portrayed as being socially awkward or anti-social as mathematicians often are.

Visitors to this website may also be interested in the fact that the writers clearly knew something about anti-matter and correctly used the mathematical term "symmetry" when a scientist character is explaining it to the others. However, the way that this bit of physics supposedly fits into the movie makes no sense sense to me. (The bird is made of matter but is surrounded by a field of anti-matter which shields it from radar and opens up when it wants to eat or grab something?)