The movie excellently captures the mood, sentiment, and creepiness of the great classic Universal horror movies of the era (Frankenstein, Dracula, et al) and has the makings of great movie in and of itself.
Not framing my expectations around the idea of this movie being a sequel to the Sherlock Holmes movie - which frankly I may or may not have seen decades ago - I'm unburdened of the task.of drawing a comparison and the apparent disappointment described by other reviewers.
The plot line is immensely workable, and the characters are all well-placed, along with a conflicted monstrous henchman, seemingly a Universal staple.
But to the movie's detriment, the movie is stripped down to its most barest elements, hence the extremely lean run time of 59 minutes. Lacking is any character development or sub-plotting that would elevate this to a "conventional" movie.
That said, I was engaged with the movie throughout. The villainous Spider Woman is stealthily creepy enough. I would have enjoyed a more fulsome build-out of the movie. And the movie, like many movies of the era, wraps up many different plot lines, almost jarringly, in no more than about 3 minutes.
All that said, this was a pleasant watch that I just happened to stumble upon on a streaming channel - with no regrets.