Game time! Cinemonster's original Hooptober 5 rules: HERE. I've pulled almost all of these from my watchlist, forcing me to get on with them already, a win-win, if you will! Here's how my list breaks down according to the rules:

10 'Anniversary Films' (Release years end in an 8, excluding 2018)
Bad Dreams (1988)
Black Roses (1988)
The Burrowers (2008)
Dracula (1958)
Martin (1978)
The Nest (1988)
Piranha (1978)
Pontypool (2008)
Slave of The Cannibal God (1978)
Slugs (1988)

6 countries
Black Roses (1988) (Canada)
Gamera 3: Revenge of Iris (1999) (Japan)
I Saw The Devil (2010) (South Korea)
The Nest (1988) (USA)
Premutos: Lord of the Living Dead (1997) (Germany)
Rawhead Rex (1986) (Ireland)

6 decades
The Cabinet of Dr. Caligari (1920)
The Black Cat (1934)
Dracula (1958)
Chosen Survivors (1974)
Tenement (1985)
I Saw The Devil (2010)

6 films from before 1970
The Black Cat (1934)
Blood Feast (1963)
A Bucket of Blood (1959)
The Cabinet of Dr. Caligari (1920)
Dracula (1958)
Whatever Happened To Baby Jane (1962)

6 films from the following: Romero, Cronenberg, Clive Barker, Terence Fisher, Sergio Martino, William Lustig (mix-and-match, or all one)
The Brood (1979) (Cronenberg, director)
Dracula (1958) (Fisher, director)
Maniac Cop (1988) (Lustig, director)
Martin (1978) (Romero, director)
Rawhead Rex (1986) (Barker, writer)
Slave of The Cannibal God (1958) (Martino, director)

2 flying things that kill you films
Chosen Survivors (1974)
Gamera 3: Revenge of Iris (1999)

1 silent film as a tribute to A Quiet Place
The Cabinet of Dr. Caligari (1920)

1 aquatic menace film as a tribute to Meg
Strange Nature (2018)

2 women directed films
Dolly Dearest (1991) Maria Lease
Tenement (1985) (Roberta Findlay)

1 inanimate object comes alive film
Death Bed: The Bed That Eats (1977)

1 film with Barbara Crampton in it
Castle Freak (1995)

2 Tobe Hooper Films
The Toolbox Murders (2004)
Mortuary (2005)

+2 to get to 31 (unofficial rules)
Idle Hands (1999)
Trick or Treat (1986)