Well this film was a Comedy/Horror :P
At the time of filming, 1955, this was classed as a Horror. A typical scene of horror in 1955 was when the main character, Reverend Harry Powell, jumps up from the bottom of the screen. Everyone in the lecture theatre yesterday was laughing at him :P
We also found it funny when the lady at the end, that takes the children in, points the shot gun at Rv Powell, and shoots him, he runs off screaming and shouting like a girl :)
This film was not recognised very well on release with the critics/audience, which lead the director, Charles Laughton, away from the movie industry. He never directed another film. The Film has a slight touch of German Expressionism, with strange shadows and strange camera angles, to create a disturbing atmosphere.
AND! It's number five in the list of films you should see by the age of 14!!! Well, According to:
(I know.. wikipedia... but thats a useful list :D)