The story is pretty forgettable, as are the leads. If you enjoy Mantan Moreland (and he is second in acting chops here only to the Lionel Atwill, who is severely underused), it's a pretty vehicle for his schtick. Plus, Shemp Howard walks through a few scenes, and there's a gorilla for no legitimate reason.
Not a great Bava film, but a good one. While sometimes crossing from dangerous into ludicrous, the film maintains tension and a sense of peril throughout. A few scenes create the cringing sympathy of later films like "Last House on the Left". I haven't seen the English language cut, but the Italian is impressive for its ability to make you believe that you've witnessed offscreen horrors.
Not a perfect movie, but one that feels important in founding the survival genre of horror.
Good dialog helps make this rather standard story pop, but the intense performance by Martin Kosleck as a vengeful sculptor anchors the film.
The continuing movie appearances of Rondo Hatton as The Creeper arguably form a significant link between monster franchises and the slashers of later cinema.