8 decades
1920s and 1 German Silent
The Hands of Orlac (1924)
1960s: Wait Until Dark (1967)
1970s: Phantom of the Paradise (1974)
1980s: Dressed to Kill (1980)
1990s: Cure (1997)
2000s: The Orphanage (2007)
2010s and 1 film with a musician or band in it
The Devil's Candy (2015)
2020s: Possessor (2020)
6 countries
Brazil: Good Manners (2017)
South Korea: The Quiet Family (1998)
Austria: The Dark (2018)
Chile: The Wolf House (2018)
Mexico: Alucarda (1977)
Argentina: History of the Occult (2020)
5 films from David Cronenberg, Ti West, Bill Rebane, Charles B. Pierce, William Grefe and/or Joy N. Houck Jr.
Videodrome (1983)
Crimes of the Future (2022)
The Innkeepers (2011)
The Sacrament (2013)
The Giant Spider Invasion (1975) and Tarantula (1955) > 2 insect centered films
2 1970s regional US films
I Spit on Your Grave (1978)
Let's Scare Jessica to Death (1971)
2 animated films
The Adventures of Ichabod and Mr. Toad (1949)
The House (2022)
2 Christopher Lee films
Horror Express (1972)
The City of the Dead (1960)
1 bloodthirsty old person/people film
Phantasm (1979)
1 Lon Chaney film
The Unknown (1927)
1 Stephen King adaptation that is not the first go around
Pet Sematary (2019)
The worst horror sequel from the 1990s
The Birds II: Land's End (1994)
1 horror film set in space or the future and 1 Tobe Hooper film
Lifeforce (1985)

Original list here.