Original list

Note: I've modified this list a few times throughout October due to some movies leaving certain streaming services. Films are ordered by my preference.

6 countries

Austria: Funny Games
Australia: Triangle
Canada: It Chapter Two, The Ritual
France: Diabolique
Ireland: Wake Wood
Italy: Inferno, Suspiria
Japan: Audition
South Korea: The Host, Train to Busan
UK: Alien, Aliens, Doghouse, Host, The Ritual, The Shining, Triangle, Wake Wood
USA: Alien, Aliens, Bone Tomahawk, Doctor Sleep, Eraserhead, Ganja & Hess, Hatchet, Hatchet II, Hatchet III, Host, The Invisible Man, It, It Chapter Two, It Comes at Night, Kindred Spirits, The Shining, The Texas Chainsaw Massacre 2, Trick 'r Treat, Vampires vs. the Bronx, Zombieland: Double Tap

6 decades

1930s: The Invisible Man
1950s: Diabolique
1970s: Alien, Eraserhead, Ganja & Hess, Suspiria
1980s: Aliens, Inferno, The Shining, The Texas Chainsaw Massacre 2
1990s: Audition, Funny Games
2000s: Hatchet, The Host, Triangle, Trick 'r Treat, Wake Wood
2010s: Bone Tomahawk, Doctor Sleep, Doghouse, Hatchet II, Hatchet III, It, It Chapter Two, It Comes at Night, Kindred Spirits, The Ritual, Train to Busan, Zombieland: Double Tap
2020s: Host, Vampires vs. the Bronx

7 2nd films of franchises

Aliens
Doctor Sleep
Hatchet II
Inferno
It: Chapter 2
The Texas Chainsaw Massacre 2
Zombieland: Double Tap

4 body horror films

Alien
Aliens
Audition
Eraserhead

2 films from this year

Host
Vampires vs. the Bronx

3 disease based films

Doghouse
The Host
It Comes at Night
Train to Busan

The highest-rated horror film from the 50s that you haven't seen and can access

Diabolique

1 film that is set entirely inside one location

Alien
Host
It Comes at Night
The Shining

1 Invisible Person film

The Invisible Man

1 Non-Dracula Hammer Film

Wake Wood

2 films with a black director or predominantly black cast or lead

Ganja & Hess
Vampires vs. the Bronx

1 film with a movie theater in it

Triangle

1 Tobe Hooper Film

The Texas Chainsaw Massacre 2