Starting this bih early because I can't wait and 31 movies is a lot of movies.

6 countries
Alison's Birthday (1981)- Australia 
Ghostwatch (1992)- UK
Ginger Snaps Back: The Beginning (2004)- Canada
Let the Right One In (2008)- Sweden 
Ringu (1998)- Japan
Scream (1996)- USA
Thirst (2009)- South Korea

8 decades
Pearl (2022)- 2020s 
One Cut of the Dead (2017)- 2010s
Ichi the Killer (2001)- 2000s
Audition (1999)- 1990s 
An American Werewolf in London (1981)- 1980s
Carrie (1976)- 1970s
Onibaba (1964)- 1960s
Creature From the Black Lagoon (1954)- 1950s

2 insect centered films
The Fly (1986)
Genocide (1968)

1 horror film set in space or the future (relative to when it was released)
The Green Slime (1968)

2 animated films
Vampire Hunter D Bloodlust (2000)
Mind Game (2004)

1 bloodthirsty old person/people film
The Visit (2015)

2 1970s regional US films
Malatesta's Carnival of Blood (1973)
Multiple Maniacs (1970)

The worst horror sequel from the 1990s that you haven't seen and can access
An American Werewolf in Paris (1997)

1 German Silent
Nosferatu (1922)

5 Films from David Cronenberg, Ti West, Bill Rebane, Charles B. Pierce, William Grefe and/or Joy N. Houck Jr.
Blood Harvest (1987)
The Fly (1986)
Naked Lunch (1991)
The Night of Bloody Horror (1969)
The Town That Dreaded Sundown (1976)

2 Christopher Lee films
Horror Express (1972)
The Whip and the Body (1963)

1 film with a musician or band in it (A real life musician or band)
Kotoko (2011)

1 Stephen King adaptation that is not the first go around.
Carrie (2013)

1 Lon Chaney film. (NOT JR)
The Phantom of the Opera (1925)

1 Tobe Hooper film
Lifeforce (1985)