Disclaimer: I’m limiting myself to streaming only because I’m tight. 

QUICK EASY RULES:

There must be 31 horror films

6 countries (other than Italy or US)
Canada: The Woman in Black (2012)
Japan: Gamera: Guardian of the Universe (1995)
Mexico: Queen Doll (1972)
New Zealand: Black Sheep (2007)
Spain: 28 Weeks Later (2007)
UK: 28 Weeks Later (2007)

9 decades
- 1920s: The Phantom of the Opera (1927)
- 1930s: The Wizard of Oz (1939)
- 1940s: Cat People (1942)
- 1970s: The Strange Vice of Mrs Wardh (1971)
- 1980s: The Texas Chainsaw Massacre 2 (1996)
- 1990s: Death Becomes Her (1992)
- 2000s: 28 Weeks Later (2007)
- 2010s: Us (2019)
- 2020s: Crimes of the Future (2022)

5 Zombie Films
- White Zombie (1932)
- 28 Weeks Later (2007)
- The Crazies (2010)
- ParaNorman (2012)
- Cell (2016)

3 cult or conspiracy horror films
- Mandy (2018)
- Ready or Not (2019)
- Crimes of the Future (2022)

1 film from a Black director with a Black lead
- Us (2019)

1 film from a Mexican or Central American director
- Queen Doll (1972)

1 Canadian film
- The Woman in Black (2012)

1 Russian or former Russian state film
- Witchhammer (1970)

The most popular film from the 1940s that you haven't seen and can access.
- Cat People (1942)

2 Post Apocalyptic horror films
- 28 Weeks Later (2007)
- Cell (2016)

1 Film with dreams or a dream as part of the plot
- Doctor Sleep (2019)

1 The animals are pissed at us film
- Black Sheep (2006)

1 Silent film
- The Phantom of the Opera (1927)

4 based on Novels
- The Phantom of the Opera (1927)
- The Dead Zone (1983)
- Cell (2016)
- Firestarter (2022)

Any film from THIS list that you haven't seen.
- The Phantom of the Opera (1927)

1 Ernesto Gastaldi written film
- The Strange Vice of Mrs Wardh (1971)

1 film from 1932
- White Zombie (1932)

I have never made a specific film a part of this before, but WIZARD of OZ ('39)
- The Wizard of Oz (1939)

And 1 Tobe Hooper Film (There must ALWAYS be a Hooper film)
- The Texas Chainsaw Massacre 2 (1986)