Stranded Sails can't have been much longer than that.

Braid is deffo under ten.

Klondike solitaire 😁.

Castlevania: SOTN once you know a couple of thing about grinding faster.

Small saga

SANABI

This game absolutely blew me away.

Journey is one of my favourite short games.

Here are some short games that I enjoyed: Untitled Goose Game, Alba: A Wildlife Adventure, Donut County, Firewatch, Tangle Tower, Agent A: A Puzzle in Disguise, What Remains of Edith Finch, Spectrum Retreat, Dust: An Elysian Tale

I just played through the entirety of Storyteller in one sitting but had a riot of a time with a few friends. I think I spent about 2-3 hours finishing the campaign and will probably spend about another hour finishing the last of the achievements when I next take a crack at it.

World of goo

Brothers - Tale of Two Sons https://store.steampowered.com/app/2153350/Brothers_A_Tale_of_Two_Sons_Remake/

Gamepad required, but pretty dope and short puzzle-ish fantasy adventure about 2 brothers who go on an adventure to get medicine for their father. Bit of a tear jerker. Few hours at most for length. If you're not into somewhat somber (or downright depressive) subjects, steer clear.

Catquest https://store.steampowered.com/app/593280/Cat_Quest/

Kinda like topdown zelda-game, but with cats and obscene amounts of cat puns. About 6 hours ish, give or take.

Gunpoint https://store.steampowered.com/app/206190/Gunpoint/

Scifi-noir puzzle platformer, ish. Basically you infiltrate, steal info, try not to be seen, get out. You climb walls/ceilings, tap into buildings circuits to control doors/lamps/elevaters/whatever to lock/smack guards to avoid detection or downright down them. Absolutely banger electronic/jazzy soundtrack. Bit janky with resolution as it is 2d game, wouldn't recommend using anything above 720p.

Perspective https://store.steampowered.com/app/1109410/Perspective/ (free!)

Another puzzle platformer, but the platformer character is separate character from "you". You move in "fps", and depending on how you leave the "camera", that forms the path for the 2d platformer dude. Difficult to explain in brief, but if you check the gameplay video it should clear it up.

What Remains of Edith Finch is a game in this category that really left an impression. Would definitely recommend a playthrough.

Brothers: A tale of two sons is pretty spectacular and can be finished within a few hours.

INSIDE is one of my favorite games of any length

Turnip Boy Commits Tax Evasion

Portal, Hyperbolica

If you're good enough, Vanquish.

Dave the Diver

Super Mario RPG can be wolluped in 20. If you go hard, I bet you can do it in 10.

Pretty fun and rather full of Easter eggs if you want to keep at it.

Hollowknight!

It seems I was mistaken