If you aren't a hardcore "puzzle thriller" fan, you might not even be aware the subgenre exists. The Cube series is probably the most representative. I've also seen Exam and The Game and The Belko Experiment. The Saw series counts, I guess, if you adopt a loose definition of a "puzzle" after the first couple movies.
As a subgenre, the puzzle thriller doesn't usually work for me. It's so intent on executing a crazy premise that, even if it's a functional success, there's no room for any emotional impact or catharsis. But the 2009 lowish-budget thriller Triangle is the rare exception. By the end of the movie, a pretty seamless puzzle is laid out that also works on a whole other level of literary and religious symbolism.
As a bonus, the film flopped when it came out, so no one's heard of it. Sadly, I can't tell you anything interesting about the plot without partially spoiling it (the puzzle thriller is basically the only genre where spoilers actually spoil movies). But you can stream it on Amazon for four bucks! Just block out an extra hour afterwards for discussing what it all means. Afterwards, come back and read the first few articles here, which cover the analysis of what exactly happens in the twisty film.
But first, here's a look at what constitutes a puzzle thriller:
List: Puzzle/survival/game movies
Okay, here's the best spoiler-y Triangle breakdown I was able to find after getting obsessed and scouring the internet. It's the third answer down, although the first two answers are useful for understanding what's going on in the movie beyond the mechanics. Even the title is a spoiler, so don't click.
This Stack Exchange answer by Kerrek SB
I thought it might help to explain just the mechanics of the events on board the Aeolus a bit to clear up what's happening.
Here's another fairly good explanation, though not as clear.
Triangle (2009): Explained, Reviewed
Bharat Krishna Swaminathan, This Is Barry
The group of people who go sailing are – Jess (main focus person), Victor (single chap), Downey and Sally (married couple), Greg (boat owner), Heather (extra, you can ignore her, the director does too). I’m going to separate them in to groups to help understand what the blazes is going on.
And that's it. There's four or five more attempts at explanation online, and most are kinda wrong. If you check out the film, feel free to tweet me and let me know what you thought. Anyway, here's some articles everyone can read.
I've always enjoyed weird music fads. Until someone writes about my trash habit of genuinely loving those ironically gritty covers of upbeat pop songs used in movie trailers, I'll have to settle for this cool music remixing technique:
The Overwhelming Emotion of Hearing Toto’s “Africa” Remixed to Sound Like It’s Playing in an Empty Mall
Jia Tolentino, The New Yorker
It’s nice to think of a handful of young people playing around on Ableton on their laptops, in their bedrooms, trying to reintroduce a sense of physical space into a listening environment of digital isolation: conjuring the sort of scenario in which, say, you’re down the hall from your older sibling who loves the Beach Boys, or in a place where, for a change, someone else controls the music—in a crowd, or at a mall, or in a pounding bathroom—someplace where you’ve taken the chance of being lonely in public, instead of retreating and clicking around alone.
I knew I had to introduce you all to this esoteric and upsetting analysis of horror movies where people's mouth stretch too wide as soon as I saw it.
This Is the Scariest Part of Netflix’s Veronica
Jordan Crucchiola, Vulture
The mouth stretch works so consistently because it escalates the terror twinge from simple shock to the threat of something unnatural. When a mousy teen girl’s mouth expands enough to accommodate a large man’s fist, you know that whatever darkness has arrived is beyond the powers of responsible adults or law enforcement to fix.
Next Week on Maddd Science: Ex Machina