Fascinating. Horrible, but fascinating.
-Contino

You don't watch a film like this because of the director or the actors in it, you watch it because Ray Harryhausen did the special effects. Not to disrespect the director though, Nathan Juran, who had a legendary career directing genre films and television even though his movies and tv shows are better known then he is.

One of the reasons the film is so much fun even when you don't have a monster on the screen is because the film seems to be in on the joke that it's filled with bad actors. It skirts the perfect tone of never taking itself to seriously and being tongue-in-cheek at the right moments.

Ray Harryhausen never hid the fact that King Kong was an inspiration for his career and this film feels almost like an homage to it. The creature, Ymir, is very reminiscent of King Kong in characterization, but not looks. He's the most sympathetic character of the film. The finale of the film even has the creature climb a famous landmark in Rome like Kong did in New York. It's in no way as good as King Kong and some people might even watch it and not notice the similarities, but it's still a great deal of fun to watch. Did I mention Ymir fights an elephant?