It's surprisingly sad.

Karloff injects a surprising amount of warmth into the monster actually. It only works if you see it as completely different to the book.

I do agree that as a standalone film it's pretty good and I can see that it definitely left a mark on pop culture.

However, I also have to agree with kellyoung that this is absolutely terrible as an interpretation of the book. Nothing that made the original story deep, interesting and horrifying is in here and the monster in the film is about the worst character portrayal I've ever seen in a film.

I don't like to throw in phrases like "The book is better" when judging a film(s plot), because I understand a film can never tell a story as deep and elaborate the way a book can. But in this particular case it is absolutely true.