Outer Wilds, the best video game I've ever played. The only downside is that it's a game that you can only really complete once (or twice with DLC). The game can be pretty short depending on how invested youi get in to the story.
The Stanley Parable is a good short game, you can be done with it whenever you want to really.
Superliminal is also a really good short puzzle game based on forced perspective and illusions. Really trippy at points.
Return of the Obra Dinn a very unique gameplay experience.
Black Mesa the HL1 remake. Really good 10 hour game. Very high quality remake that makes a good improvement on the first.
Ultrakill, EA boomer shooter with lots of cool mechanics.