Straight from the trivia section of IMDb: "Roger Corman gave Coppola the task of creating two monsters resembling genitalia (one male, one female) which were amusingly spliced into the film." Yes, the most famous thing this movie is known for, was actually not even in it originally! I mean look at the front of the movie:
I love how they put his name right on there as director. He probably filmed about 20 seconds of footage in the entire film. But, he's famous so, add him in there! We've obviously seen this before, usually when an actor that would later become super famous was put in some second rate slasher like Cutting Class (1989).
I wonder what type of payoff the original film, Nebo zovyot, had. The cover of the movie is the final payoff of the American film, which isn't quite a spoiler if you've seen Corman, or is you're familiar with 50's monster movies. It's all a lead in, Mars is the target for both Russian and American astronauts. It's a toss up of who is going to win, but since the movie is Russian, they do eventually arrive first. And this huge vagina beast is what awaits them. Which is cool, I guess.
This movie had a ton of lead in, not a lot of pay off, and was very much a genuine 1959 flick. It has the pacing, the feel, etc. It is color, which wasn't hugely popular at the time especially among the normally low budgeted science fiction genre. It's also a very quick hour and 17 minutes, over before you know it.
It's not hugely memorable, the end monsters are obviously the best part, and getting to that end part I'll rate as "good/average". Also, given the names attached, it is one of the better known classic sci fi movies, and I'd known the cover of it long before I'd seen the movie. Anyways. It's fun, but be prepared for slowness and not a lot of interest factor.