There must be 31 films
One film can work for multiple categories

6 countries:
Japan: Ju-on: The Grudge
Germany: Funny Games
France: Eyes Without a Face
South Korea: A tale of Two Sisters
Spain: Pan’s Labyrinth
Austria: Goodnight Mommy 

8 decades:
1920s: The Man Who Laughs
1950s The Hound of the Baskervilles
1960s: The Birds
1970s: The Vampire Lovers 
1990s: Scream
2000s: The Black Dahlia
2010s: Get Out
2020s: Dracula

2 post apocalyptic or natural disaster related films
The Last Man On Earth
28 Days Later

1 film with Robert Englund
Zombie Strippers

1 something is underground film
10 Cloverfield Lane

3 Satan/Devil centered films
The Witch 
Drag Me to Hell 
Rosemary’s Baby

1 Amicus film. 
Tales from the Crypt

The worst Dracula film (by Letterboxd rating) that you haven't seen and can access. 
Dracula (2020)

1 LGBTQ+ connected film
Black Swan

5 Films from De Palma, Wes Craven, Ken Russell, Hitchcock and/or Moorhead & Benson.
The Birds
Carrie
The Black Dhalia
Scream
The Devils

2 Peter Cushing films
Tales from the Crypt
The Hound of the Baskervilles

1 film based on a work of or invoking the name Bram Stoker
Nosferatu

1 film based on a Clive Barker story
The Man Who Laughs

1 film that was released the year that you turned 10
The Host

1 Mario Bava film 
Four Times that Night

1 film with an 'x' in the title
The Exorcist

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