I tend to look around Steam for various games and demos that barely anyone knows about. Some of them are actually pretty good and innovative, so I'll list them here.
Demos
The Oversight Bureau
There are some major Severance vibes with this one. The premise is this: For reasons unclear, you are a subject in a rehabilitation program, designed to help you fit in with society. There are some fun, simple Portal puzzles on Day 2, and a fun puzzle on Day 1 where you need to guide someone out of a burning building by telephone. A very unique part of this game is that you need to use your microphone to give commands and answer questions, and the bots you meet on Day 2 can handle commands pretty well.
Fractured Blooms
In this one, you play as a woman in a rural area, dedicated to caring for plants on her property. Another part of her job is managing the bothersome SCP causing trouble. There are some weird entities on the loose, and keeping to the routine is how the MC keeps them placated (as far as I can tell).
Alice's World
This demo is for a game that will be released later this year. The MC, Alice, finds herself in a dead world where bizarre creatures are on the loose. She also lets you pilot her around to investigate things, and comments on what's going on from time to time.
It should also be noted that this game is big on metafiction. The nature of it feels like a mixture of DDLC and Spec Ops The Line.
Cycle of Struggle: Ardengrad
It's a VN, yes, though this game is about a post-Soviet country facing an upcoming revolution in an alternate reality. The country is deeply divided, and if the start of the demo is any indication, there's also some funny business going on with the city's power plant. It feels like a mix between V for Vendetta, S.T.A.L.K.E.R., and a dating sim.
Games
Redshift
This one doesn't take very long, and it's free. Basically, you show up at a spooky radio tower to go turn the thing on, at which point you need to evade an entity that chases you. The premise is straightforward, though I like how you need your character to close his eyes to see the monster.
Ameshidama
This is another free one. You'll like it if you're into escape room games. There are two sets of rooms to solve, and one chase to deal with at the end. The protagonist never actually talks (for certain reasons), though you do see her thoughts from time to time. In fact, the story is mainly told through picture books. An interesting puzzler that went under the radar.
Days Without Incident
If you've ever played Nightmare House 2 or In Sound Mind, this is the small game that the devs of those two games made in between. It's a short game that mainly involves you exploring a creepy factory. I advise entering this one blind.
60 Minutes to Extinction: Escape Room
This is the latest entry is a series of escape room games by mc2games. The games from these devs are all about the puzzles, and this one introduces a time limit. This game is easier than the other entries in the series, though I like the puzzles regardless.
Mods
vp_downcorridors Part 1
This one is actually a mod for Gmod rather than a standalone game. This map, along with the other maps in this series (called voidplaces), are set inside a Backdoors-esque location with a strange pink Sun shining overhead. In this particular map, you make your way through some Portal-looking puzzles before you're let loose inside the downcorridors facility. Voidplaces is big on exploration, so be aware of that before trying this out; exploring all there is on this map will probably take awhile.
I nominate DLSite and JAST.