In the silent void of outer space, puny man matches his cunning against a monster from Mars. A group of likeable Joes and Janes in space land on a mysterious planet for something of a rescue mission; and once they have left and are back in space they realize they have some THING on board, and it proceeds to open a can of whup ass on the entire crew. Sounds like Alien and plays out like a true precursor. As far as old sci-fi goes this is very watchable. If you have kids, think of it as a tame version of Alien you can share until they are actually old enough for the stomach burst scene, et al. The parallels are quite endless, right down to the iconic 'shooting the shit' scene around the mess in which we meet everybody.