The film that introduced Hammer Films to horror. British television star Peter Cushing played Baron Frankenstein, Christopher Lee was the monster, and Hazel Court began her career as The Queen of Scream (although she had been in movies for more than a dozen years), setting the standard for Hammer heroines, big screams and big cleavage (Court's autobiography was called Horror Queen). Frankenstein is far more the center of this film than is the monster, and Cushing is as good as anyone has been as the Doctor. Lee is hampered by his makeup, which was created shortly before shooting began, looked cheap (albeit ugly enough), and didn't give Lee much chance to draw our sympathy the way Karloff did.
The biggest problem with the film is that the first half, wherein Frankenstein works to perfect his ability to create life, is kinda boring. It was a big hit in its day ... some attribute this to its being in color, thus letting audiences get a better experience when watching the gore. As you might expect, the gore, however shocking it was in 1957, barely raises an eye today.
There's nothing really wrong with The Curse of Frankenstein. The acting is good, and for such a low-budget film, it has an attractive look to it. But all in all, nothing special.
The quick shot of Peter Cushing looking into the magnifying glass brought this scene instantly to mind: