It’s easy to see why the Frankenstein sequels from Universal struggled; they had to live up to the high standard set by "Frankenstein" in 1931 and then “The Bride of Frankenstein” a few years later. Those are incredibly difficult movies to surpass—and still are! “Son of Frankenstein,” released in 1939, did a decent job, featuring Basil Rathbone and Bela Lugosi delivering strong performances as Ygor. Boris Karloff stepped away from playing the monster after that film, creating a lasting image and sticking to the idea that the creature shouldn’t speak. Whether or not that was necessary for giving him personality is something Frankenstein fans still debate—is he better off being just a force of destruction? In this movie, however, he does get a voice, thanks to Lon Chaney Junior taking over the part, but it doesn't quite work out well. “Ghost of Frankenstein” marks the beginning of the franchise’s downfall, with a clear decline in overall quality. It felt as if Universal realized they had a moneymaker and prioritized making lots of films over making good ones. They would eventually pair the monster with “Abbott and Costello,” which led to some entertaining moments, but the scary elements started fading away in 1942. Lugosi returns for more Ygor antics, while Cedric Hardwicke and Lionel Atwill portray scientists with differing viewpoints—their presence is comforting. Evelyn Ankers looks good and her costumes are well-designed. The film’s short running time of just 67 minutes prevents it from becoming tedious, even though there isn't much action; thankfully, there’s some castle demolition and fire!. The cinematography by Woody Bredell and Milton R. Krasner consistently creates a Gothic mood. Now it’s on to Universal Monster Team-Ups... 5/10

Source on TMDB