Outerwilds is a beautiful game and quite short, try to go in as blind as possible. It's space archaeology.

Gris is an art game that's about 3hrs long. Very pretty, very zen.

Into the breach, is a puzzle game (chess vibes) where you are time travellers saving the world from insect aliens. has a long time to beat, but play sessions are fairly short. I think it's a great game for when you are taking short breaks between something else. it might be a tad too on the roguelike side for you, but it's primarily about solving puzzles.

Carrion is a puzzle-horror game that took me about 5hrs to beat, it's extremely satisfying

Nauticrawl is a very esoteric game, you pilot a sub at the bottom of the ocean and have to learn from scratch how to pilot it. If you like doing stuff with no instructions you'll enjoy it.

Not for broadcast is a shortish (~20hrs) game where you control a live action broadcast and get points for how well you do cuts... or censor people

Superliminal is a 3hr puzzle game that plays with size and perspective.

A short Hike: It's a pretty short relaxing game. Low stake, no stress.

Chained Echoes: I don't know how long Octopath 2 is, I only finished the first game, but since you mentioned it you may like this one. It's a turn based rpg, but there is basically no grind. Your party is fully heal between each fights. It's quite respectful of a player's time in that way.

How far did you get into Subnautica and what turned you off about it? I understand it's not for everyone. It can be a little bit obtuse in the way it gates your progress behind radio transmissions, and if you don't find the right blueprints your journey can be made much harder or easier respectively. I've been replaying it recently and I can see how it'd be hard to get into. One thing to note is that as you advance a lot of the annoyances of finding food, water & power to upkeep everything get eased through different technologies, so you slowly get more freedom from the grind, and the story is worth seeing to the end. In fact every new tech makes the game easier and faster and opens up the world that much more, either by making it easier to traverse long distances or go deeper, or carry more, etc. The early game is slow and frustrating in comparison.

I could cosign a bunch of suggestions already, but Outer Wilds is one of my favourite games of all time. I'll try to explain it without any spoilers: It doesn't gate your progress behind anything but your own curiosity and acquired knowledge. It also gives you a sense of freedom that you get from fully simulated physical movement in space. It is also deeply emotional and if you're halfway to the end wondering, "How could they possibly stick the landing on this and end it well?" the answer is just trust, omg it's so good. You can't really experience it twice - it's designed such that when you possess the right knowledge, you can finish the game extremely quickly, but also to do so you must truly understand and master the ideas you are being taught - so you can only experience it again by watching blind let's plays. I've watched 4 so far and each one was a moving experience watching the person go through their own process of understanding over many, many hours.

If you like platformers, Teslagrad is a beautifully illustrated and impeccably designed metroidvania which I've played through many times. All the story is delivered through puppet shows rendered within the levels themselves and gorgeous collectible cards. They've just released a remastered version with a number of QoL changes that I'll be playing again, and the sequel is out. I believe they're still available in a Fanatical bundle right now.

The metroidvania that got me into the genre is actually a free game by the maker of Celeste, from many years ago. It's called AnUntitledStory and I've played it through many times. Some quite hard platforming challenges but the whole aesthetic is extremely cute, and as you'd imagine from the dev of Celeste the controls are crisp and precise.

Hollow Knight is another incredible metroidvania/souls like. You play as a bug in the ruins of an ancient civilisation of bugs and it is quite haunting. Again, amazing aesthetic.

And if you want something chill instead, I'd go with Spiritfarer. You build your boat and travel the spirit world helping souls on their journey to the afterlife, except each soul is unique and has their own personal needs and closure you help them achieve before they're ready to pass. Most importantly you can pet your cat whenever you want, which every game should have.

Please consider WanderSong. It's a small game and was made with so much love. Games can have a huge variety of plots and environments. But the vast majority of games, regardless of what they are about, are actually about victory. You're a space dwarf mining for minerals, but the game is all about mastery and winning. You're a dragon-kin with magic shouts, but every quest is about achieving a victory over a challenge. And so on.

I would say that WanderSong is not a game about victory. It's a game about happiness. The character, the mechanics, the plot, the environments; they all serve first to explore the meaning of happiness. There's nothing else quite like it. You can find it here.

Have you heard of Hardspace: Shipbreaker? If anything it's the opposite of a crafting-building game, it's a disassembly game! It's set in space and has a nice plot about corporate greed. And you have to manage your oxygen in space, so arguably it's like diving, haha.

Another game I liked that's made by a small studio is Carrion. You play as a The Thing-esque monster that has to kill, grow, and solve different puzzles to escape the lab it was created in. Very gory but fun.

Steamworld games?

I haven't beat all of them but Dig 1 and 2 are definitely way shorter than I wanted (I'd pay full price for an endless mode DLC lol).

Except Hades, Supergiant games aren't super long. Bastion and Transistor are decent, and Pyre might be a little longer but is pretty unique.

I'm interpreting your list of games as semi-casual with a strong unique flavor. The messenger is a little harder than the others but still not super long.

This might not be exactly what you're looking for (as it can be a little rogue-like), but it's a game that when I looked for similar things, led me to Dredge: Sunless Sea

You're a ship captain trying to survive in Victorian era London, after London was stolen by bats and taken to the shores of the Unterzee, an underground sea filled with some very strange creatures, people and locations. This means exploring and finding new trade routes or ways to survive while uncovering the stories of the islands you find, those of your crew, and the larger world.

There's a sequel, Sunless Skies, where you command a space going train exploring the heavens. It's a bit easier and has some good quality of life improvements, but I prefer the setting of Seas.

oh do u like metroidvanias? Apotheon is pretty short and has absolutely beautiful art.

Gone Home is a calm little exploration game u can complete in an afternoon, but it has plenty of secrets to find if u wanna dig around.

Creeper World 4 is fun and not terribly long. It is basically a tower defense game, but instead of guarding a set path toy build towers to defend against, then push back, physics simulator liquid that kills whatever it touches.

Shadow Tactics: Blades of the Shogun, you play a small group of ninjas (and a samurai) in a top down stealth game. Takes place in feudal Japan and you assassinate your way through the plot.

Superhot. FPS with a weird plot about VR and a rogue computer program. The gimmick is if you stop moving, time stops around you (almost), allowing you to slow down and plan.

Lastly and is a game called Soccer Kids Alpha. It is literally the alpha version of the game so it is SUPER short. It is a turn based soccer game, but without the grid based system that some other games use. The alpha is great and we'll worth the very short time it takes to finish

Since you named Octopath Travellers 2, I'll recommend Cosmic Star Heroine. It's an old school turn-based indie JRPG that's charming, fun and short. As a matter of fact all games by Zeboyd fit that description.

hypnospace outlaw is a great puzzle game with some excellent world building. it literally feels just like old internet days. and the music is fantastic "ready to shave" is a legit amazing song, even if its a prog parody about a man shaving

Haven't played observer, but the aesthetic and horror aspect remind me of SOMA.

If you want something more action focused with a cyberpunk aesthetic, I can't recommend Distance enough. (If you need a pitch: racing game with horror and your car can fly). I also just started playing Severed Steel and I'm enjoying it a lot so far.

I will also concur with the other person who recommended Outer Wilds. Don't look up anything about it, go in as blind as possible, and try to see it through to the end. You will not regret it.

Observation is one I really enjoyed. Mild puzzling, tension but not really the sort that kills you, and a fun, mind-bending story. Also the title track is just amazing.

I'd like to recommend Pentiment. Narrative-driven game set in the Middle Ages, or rather at the end of the Middle Ages. It has an interesting story and according to some historians it's historically accurate. I loved the story, the setting, the art...

Watch a review or something and give it a try if you find it of your liking.

I loved Killer Frequency! I made a post talking about it.

Procession to Calavry is a point-and-click adventure game tagged as "medieval" and "dark comedy" which is spot on.

The Longing is a pretty experimental game about waiting. You can win the game by waiting 400 hours, or you can go for one of the alternative endings, all of them needing a lot of waiting around.

Return of the Obra Dinn is a game you should take your time in. Explore. Ponder. Explore. Ponder. It has been compared to filling in crosswords.

Ittle Dew is a puzzle game with a Zelda-ish style and cute punk comedy presentation.

One Finger Death Punch 2 makes you feel the way super cool martial arts fights scenes look.

If you don't mind some puzzle solving and the fact it's a point and click adventure game, there is Beyond The Edge of Owlsgard. It can be completed in a couple hours if you have played it before, but took me so much longer since I had no prior experience.

There is also Brok the Investigator, which is a choice based game where your actions lead to one of something like 6 different endings before, supposedly, getting the cannon ending or something along those lines.

Honestly, there are two mobile games I've really been blown away by: Night of the Full Moon, and Dungeon Boss Respawned. They're very polished, very feature-complete games that are on the small and neatly contained side. For PC, Bastion is pretty damn good. Dungeon Keeper 1 and 2 as well, but it's difficult to get those running anymore. Raft, Ori and the Blind Forest and Stardew Valley are also phenomenal.

I'm sure there are other small games worthy of mention, but I'm struggling to remember them. I usually play large open world games. On that subject, absolutely try Valheim if you haven't.

I'll be happy to summarize each of these games if you'd like me to.

I would highly recommend A Story About My Uncle. It took me about 6 hours to get all the things and do the whole story. It's a somewhat challenging first-person platfomer. Basic setup for the story is your Uncle is an inventor and adventurer. He disappeared and you find a note and a device in his attic, the device teleports you to a different world/dimension, and you make friends and find adventure along the way.