Portal?

Outer wilds. It can be longer for some but finishing it in a single sitting or two it hits best. A deep emotional experience that you can only ever truly experience truly the first time. So avoid spoilers at all costs.

Also Firewatch

A Short Hike is a great little platformer you can finish in a couple hours.

Super Mario RPG is a classic and can be squeezed into 10 hours if you rush, but probably closer to 12~15.

Mirror's Edge - a perfect way to spend 5 hours

Journey is a game that has stuck with me for the past ten years. It took me an hour and a half to complete.

Ordered-ish by recommendation:

• SUPERHOT (it's the most innovative shooter I've played in years)
• Hellblade: Senua's Sacrifice
• Sayonara Wild Hearts
• Carrion
• Planet of Lana
• Jusant
• The Artful Escape
• The Gunk

I always check https://howlongtobeat.com/ before starting a new game

I also tend to prefer games that are short.

Here are a couple of my PC recommandations, in no specific order :

Somerville

Jusant

Planet of Lana

Limbo + Inside

Little Nightmares 1 + 2

Cocoon

Solar Ash

Tunic

Cult If The Lamb

Have A Nice Death

Death's Door

Stray

Trek To Yomi

The Stanley Parable

I also love short-ish games, so hopefully one of these strikes your fancy. You didn't specify a preferred genre or other games you liked, so I'm going to just throw some out there:

Adventure/Puzzle

• Stacking - fun adventure puzzle game based on matryoshka dolls
• Little Nightmares - fantastic puzzle game stuff great atmosphere and horror elements; similar to INSIDE and Limbo
• Abzû - underwater exploration with light puzzle mechanics
• Ys 1 and 2 - pretty old, but it's my favorite Ys game; Ys Origin is a bit newer, but also a bit longer (~11 hours per playthrough, need 3 for full story, but each plays differently)

Puzzle

• Manifold Garden - puzzle game where you manipulate gravity
• Hexlogic - sudoku-like
• SUPERHOT - shooter that plays like a puzzle game
• Magrunner - just ignore the story, the puzzles are pretty good
• Portal - the OG puzzle game, must play if you haven't; second is about twice as long

ARPG/Souls-like

• Death's Door - just started, but it's looking good
• Ittle Dew - Zelda-like with lots of satire about the genre
• Furi - boss rush only
• Titan Souls - boss rush, but both you and the boss has 1HP

Narrative heavy

• Telltale Batman or The Walking Dead - narrative heavy game with walking simulator sections; choices matter (but not a ton); great if you want a decent interactive story
• What Remains of Edith Finch - explore your old home to learn everyone's secrets
• Oxenfree - explore Island to uncover its secrets; replay value for alternate endings

Metroidvania

• Headlander - Metroidvania where you play as a disembodied head that can attach to other bodies
• Ori and the Blind Forest

Point and Click

• Darkside Detective - point and click with a great sense of humor
• Broken Age - you're a virgin about to be sacrificed, and you're not sold on the idea
• Deponia - earth is completely wrecked, and you want off; quite funny

AAA/high production value

• Ryse: Son of Rome - not amazing, but a pretty satisfyingly average experience
• Call of Juarez: Gunslinger - shooter a bit after the US civil war

I have more, just let me know what you like and I can try to give more recs.

Well-reviewed games you can 100% in less than 10hrs:

• Portal
• The Henry Stickmin Collection
• OneShot
• Stray
• Grimm's Hollow
• Any of The Room games
• Pineapple on Pizza
• There Is No Game: Wrong Dimension
• Doki Doki Literature Club
• TOEM
• Finding Paradise
• The Murder of Sonic the Hedgehog
• CULTIC
• Gorogoa
• The Case of the Golden Idol

Well-reviewed games you can probably beat in around 10hrs, but not quite 100%:

• Portal 2
• Vampire Survivors
• Pizza Tower
• Katana ZERO
• A Hat in Time
• Resident Evil 2
• Hotline Miami
• The Wolf Among Us
• Undertale
• Papers, Please
• Baba Is You
• DUSK
• POSTAL 2
• Outlast

Edit: formatting is pain

Edit 2: I missed the part about low-end hardware, but it sounds like the only ones of these you may not be able to run are Stray and Resident Evil 2

In no particular order:

Metal Gear Rising Revengence

Psychonauts 1

Bladed Fury

Ori and the Blind Forest

Titanfall 2

OneShot

Undertale

Unpacking

Portal/Portal 2

Bastion/Transistor

Any member of the Shadowrun RPG trilogy

Little Inferno

Planetarian

Antichamber - old revolutionary puzzle game, confusing at times
Baba is you - a great puzzle game
Outer wilds - experience that is one in a lifetime, go in blind
Return of obra dinn - you are a detective

If it hasn't been mentioned, I think it's newer than 5 years but Return of the Obra Dinn and Curse of the Golden Idol are great short games that you can pick up and put down as you like.

Games of about 10hs from before 2019?

• King of Dragon Pass: Tribe management game/text adventure with illustrations. Felt it was interesting in both mechanics and vibes
• Plants vs Zombies: Addictive comedy-themed tower defense
• Alundra: PS1's Zelda
• Gris: Atmospheric 2D puzzle platformer
• Celeste: Rewarding 2D platformer with nice music
• The Lion's Song: Graphic aventure light on gameplay and heavy on story and atmosphere. 4 chapters about early 20th century Austrian artists and scientists with themes like art, gender, identity, memory, society, etc.
• Orwell: Keeping an Eye on You: You play as a government employee tasked with finding people deemed as terrorists by the gov by scouring their social networks. There's different ways to play it
• Papers, Please: Similar to above but as a border control agent
• The Banner Saga: Tactical RPG bases on viking mythology
• Rebuild: Gangs of Deadville: Management of a group/colony of customizable survivors in a zombie apocalypse. Web game

These are more recent but they should require very low specs:

• Roadwarden: Very well written and immersive text adventure with RPG elements. Low fantasy world, you're assigned as a roadwarden by a far away nation to a dangerous and sparsely populated wildland.
• Landnama: Viking tribes settling Iceland. Plays like a well designed board game in video game form. Real time with pause.
• Citizen Sleeper: Incredible cyberpunk text-heavy adventure with RPG elements and a narrative focused on being humane in a not so humane world with a not quite humane body

Portal 2

You absolutely must play Doki Doki Literature Club if you have not. It's free. Do not look up spoilers or be put off by the type of game or the setting. Just play it.

P.S. - "Doki Doki" the way you write the sound of a heart beating in Japanese akin to "lub dub" in English.

Return of the Obra Dinn. The 2nd game from the maker of Papers, Please. You're trying to solve the murders or disappearances of 60 people on a ship, using a watch that can view their moment of death. Insanely unique game, and it's hard to replicate that feeling of all the pieces of the puzzle falling into place that this game fosters.

Titanfall 2 is fun! I did the singleplayer in about 6 to 7 hours.

I have seen it recommended somewhere in the comments but I want to shed some more light on this game: What Remains of Edith Finch. It is a walking simulator that should take about 2 hours and is best played in a single session.

As Edith Finch, you go back to the house where you grew up in your younger years to explore it. The Finch family has an almost genetic trait of bad luck; many of them have died before their time. You explore the house room by room and explore that person's last moments.

There is no gore or horror of any kind, but there are children that die, so if that is a trigger I would sit this one out. If not, it is currently on sale for less than €5. It is worth it.

Stray

Celeste. Not much to say except that it's a fantastic little platformer.

I think Bastion is a perfect fit for this

Stray

Chrono Trigger apparently. It feels longer, but if you are familiar with square rpgs… or Pokemon. You can get through it quickly.

I take my time personally, and like doing the side activities, and listening to the music.

I don't think anyone else has mentioned Gunpoint! So.. Gunpoint.

• Eliza: A visual novel by Zachtronics, took me 10 hours to beat

• Aviary Attorney: A visual novel / detective/ attorney game with music from Camille Saint-Saens and art by J.J. Grandville. Beat it in 7 hours and had a blast.

• Braid: 2D puzzle platformer with time shift mechanic. Finished it in 7 hours.

• Tiny Bang story: wimmelpicture point & click. 7 hours.

• Call of Cthulhu: Horror walking simulator. 7 hours.

• Bastion: Amazing isometric action game by Supergiant Games. Rook me good 6 hours to finish.

• Thomas was alone: 2 D platformer with geometric shapes as characters and great narrator. 6 hours.

• Whispers of a machine: Noir detective story point & click. 5 hours.

• Homefront: USA gets invaded by Korea first person shooter. Good 4 hours.

• INSIDE: Atmospheric 2D puzzler. 4 hours.

• LIMBO: Same as INSIDE, same developer, great game, different story. 4 hours.

• Firewatch (highly recommend!)
• SUPERHOT
• The Stanley Parable: Ultra Deluxe (highly recommend!)
• Frog Fractions (game is best played blind)
• SCP: Containment Breach

Incremental Games: (best played blind)

• Skynet Simulator (highly recommend!)
• A Dark Room
• Crank
• Candy Box!

I keep a spreadsheet literally called "games to play". Ive played about half of these so far, but they all meet your criteria, and all have overall good reviews, here's a selection from it, including my own notes: (pardon the lack of formatting coming from a spreadsheet)

A Hand With Many Fingers - 3 hours - Puzzle - Difficult (use pen and paper for clues) CIA mystery

A Wolf In Autumn - 1 hour - Walking Sim - Girls nightmare

ADR1FT - 6 hours - Puzzle - Space station catastrophe

Anna - Extended Edition - 5 hours - Adventure - Psych horror in sawmill, inventory based puz

Antichamber - 7 hours - Puzzle - MC-Escher-esque open world physics breaking puzzle solving

Aporia: Beyond The Valley - 5 hours - Walking Sim - Walking Sim+ (puzzles), awaken in ancient temple in jungle

Ballads At Midnight - 4 hours - Visual Novel - Story of a bard and a vampire

Beyond: Two Souls - 12 hours - Adventure - Ellen Page / Willem Dafoe,

Blind Spot - 5 hours - Puzzle - Puzzle mystery story

Brothers - A Tale of Two Sons - 3 hours - Walking Sim - Heart-wrenching story told with no words

Brukel - 1 hour - Walking Sim - 92yr old grandma retells memories of WWII

Close To The Sun - 6 hours - Walking Sim - Looks like Bioshock, great atmo

Cloud Climber - 1 hour - Walking Sim

Deliver Us The Moon - 5 hours - Adventure - Sci-fi story on moon, some puzzles, some platforming

Dr. Langeskov, The Tiger, and The Terribly Cursed Emerald A Whirlwind Heist - 1 hour - Walking Sim - Very short, hilarious game from maker of The Stanley Principle

Draugen - 3 hours - Mystery - American searching for missing sister in 1920s Norway

Goetia - 7 hours - Point-And-Click - Puzzles / adventure in abandoned house, text heavy

Gorogoa - 2 hours - Puzzle - Hand Illustrated puzzle game

Heavy Rain - 10 hours - RPG - Crime thriller / mystery, multiple outcomes, some QTEs

I Hope She's OK - 1 hour - Walking Sim - Short mystery at a nordic cabin, told through instagram-like messages

Jessika - 3 hours - FMV - Solve suicide of Jessika

Journey - 5 hours - Walking Sim - Atmospheric exploration

Knee Deep - 4 hours - Puzzle - Mystery in a swampland / theater production

Kona - 8 hours - Adventure - Detective in eerie Canada town

Manifold Garden - 6 hours - Puzzle - M.C. escher landscape build gravity bend puzzles

Murdered: Sould Suspect - 10 hours - RPG - Solve your own murder

Scanner Sombre - 3 hours - Walking Sim - Trippy cave-explore game

SOMA - 10 hours - RPG - Horror adventure

Tacoma - 4 hours - Walking Sim - Sci-fi space station adventure

The Fidelio Incident - 3 hours - Puzzle - Short story, plane crash in N. Ireland

The Forgotten City - 10 hours - RPG - Time loop in ancient Rome

The House of Da Vinci - 7 hours - Puzzle - Similar to "The Room" series

The Painscreek Killings - 10 hours - Walking Sim + - Murder mystery, find clues and keys

The Secrets of Darkwood - 5 hours - Txt RPG - Descendant of Might and Magic series

The Signifier - 9 hours - Adventure - Dark, tech-noir

The Silent Age - 4 hours - Point-and-click - Short, fairly easy puzzles, time travel post-apocalypse

The Turing Test - 6 hours - Puzzle - Portal/Talos wannabe

The Unfinished Swan - 4 hours - Puzzle - Paint / blob game

To The Moon 4 hours - Walking Sim - Doctors help dying patients relive life

Untitled Goose Game - 6 hours - TP-RPG - You are a horrible goose

Valley - 8 hours - Walking Sim - Actually running/jumping sim

Of these, the standouts that I've played so far are "Scanner Sombre" and "Unfinished Swan" for truly unique gameplay. "SOMA" and "Heavy Rain" for best storytelling. "Painscreek Killings" for best mystery (minus one very out of place sequence). "Forgotten City" for the best standalone Skyrim mod turned into a self contained adventure.

Celeste!

(Unless you want to complete additional levels, which are still canon, then much much more).

Limbo. Good game and it lasts only 2 hours.

It's been awhile since I finished if, but if I recall correctly,Abzu was about 5 hours.

Bulletstorm, its stupid, its raunchy, and its hilarious, and it clocks in at about 8 hours.

Bioshock comes to mind. You'll miss some side stuff with a 10hr play through but I think it's doable. Amazing game

I enjoyed Stray. It’s pretty short, only got stuck one 1 of the puzzles.

Journey

Inside

Adrift

Subnautica

Humanity