There must be 31 films....

Original list: The Twelfth of Hooptober: Diary of a Madman

Countries:

Australia: Bedevil
France: Martyrs, Vampyr
Canada: Martyrs
New Zealand: Braindead
Japan: Audition, Onibaba, Suicide Club
Germany: Vampyr, Nosferatu
Spain: All the Colors of the Dark
Lativa: Spider
South Korea: Train to Busan

Zombie Movies:
- Corpse Bride
- The Return of the Living Dead
- Return of the Living Dead Part II
- Braindead
- The Evil Dead

A Film About Dreams:
- A Nightmare on Elm Street

Cinemonsters All Time List:
- Audition

Film from 1932:
- Vampyr

Silent Film:
- Nosferatu

Based on a Book:
- Doctor Sleep
- Nosferatu
- Frankenstein
- Suspiria
- Tromeo & Juliet

Post Apocalyptic:
- Phase IV
- Train to Busan

Most popular from 1940s that I can access:
- Cat People

Tobe Hooper Film:
- The Texas Chainsaw Massacre

Black Director with a Black Lead:
- Blacula

Mexican Director:
- Frankenstein

Film from a former Soviet State (Latvia):
- Spider

Cult/conspiracy films:
- Suicide Club
- Doctor Sleep
- Suspiria

Decades covered:
- 1920s
- 1930s
- 1940s
- 1960s
- 1970s
- 1980s
- 1990s
- 2000s
- 2010s
- 2020s

Bonus:
- Trick or Treat
- Burn Witch Burn
- The German Chainsaw Massacre

I have some other bonuses too at the bottom if I get extra time :)