I've watched peeps do this "watch a bunch of horror movies leading up to Halloween thing while following certain specifications" thing for a couple of years, but I never jumped on it myself. Gonna give it a shot this year. I'm challenging myself by watching one movie for each criterion for the challenge, effectively having each movie that "counts" fulfill only one criterion despite most overlapping several.
Check out the notes to see which criteria each movie fulfills.
Here's a link to the original post kicking this thing off: letterboxd.com/cinemonster/list/hooptober-cinco-your-terror-is-a-locked-room/