This isn't just mindless crap!

After recently seeing this film, I initially thought that it was amusingly terrible- the poor effects of the alien etc.
This is hardly the film's fault though, having a 50's B-Movie budget and limited technology, but it is a meaningful film, especially given the context in which is was made.
1950's America, not long after World War 2, and there was a growing fear of a Communist overtake. This is expressed in the film, and I believe that to some extent, the alien represents Communism.
There is also a strong moral overtone throughout this film; about the importance of emotions in relationships and society. In this film there is an Orwellian feel, with the controlling party erradicating emotions for a "better world".
Most of the other people that I know who have seen this think it is just a silly piece of film that they won't ever think twice about again, which I think is a shame.
It turns out that it's more than it looks. It isn't mindless crap