I haven't seen this movie in 46 years, but the thing I remember about it is the fact that I was so terrified watching it, at nine years of age at the Lincoln Theatre in Kearny, NJ, that I had to leave before it ended. I didn't sleep well for many nights after that.
There was a scene I remember where a crew member opened an air duct access hatch (or what, as I recall now, looked like one), and a hand fell down in front of him, obviously belonging to a dead colleague of his. The creature had stuffed the body in the ductwork. That was all I could take. I threw my comic book (I always bought one for 10 cents on my way to the movies on Saturday afternoons. My mom would give me 35 cents, 10 for the comic and a quarter for the double feature with cartoons in between) up in front of my face so I couldn't see, and ran up the center aisle, out the doors, and away from that horror. I saw just about every monster/horror/sci-fi movie made in the 1950's on one or another of those wonderful Saturdays at the Lincoln Theatre, and the only other one that made me run out was House on Haunted Hill.
What I wouldn't give for another chance to see two movies and three cartoons for a quarter, through the unjaded eyes of a nine-year old boy, still able to be scared out of my wits by a guy in a rubber suit.