The Shivah
Blackwell Legacy
Blackwell Unbound
Blackwell Conversion
Blackwell Deception
Gemini Rue
Puzzle Bots
Jolly Rover
To the Moon
Ben There, Dan That
The Stanley Parable
A Story About My Uncle
The Ballads of Reemus: When the Bed Bites
Hector - Badge of Carnage (a single episode, that is; I guess the same would apply for most Telltale games)
Samorost 1&2
Thomas Was Alone
Anodyne (unless, like me, you get hopelessly stuck near the end due to the jumping mechanics )
Escape Goat
Soulcaster I & II
Iji
Trauma
Superbrothers Sword & Sorcery EP
Dwarf Quest
Little Inferno
Laser Cat
Nightmares from the Deep: The Cursed Heart (if you don't mind trying a HOG)
Possibly (not quite sure from memory): Time Gentlemen, Please!
Emerald City Confidential
Primordia
VVVVVV
Waking Mars
Hotline Miami
Possibly (just guessing, I haven't completed them yet): Unmechanical
Qasir al-Wasat - A Night in Between
Freedom Fall
Rico - A Tale of Two Brothers
Beast Boxing Turbo
Zeno Clash
mondo84: Home can be completed in about an hour or so.
Sachys: Really? I think I spent about an hour and a half on it and haven't gotten anywhere yet - might just be me though - I seem to keep losing track of my goals.
I know it definitely took me longer than an hour, too, but I think the feeling of not getting anywhere is inherent to the game and not dependent on your progress. ;) It fits the label of a short game, but personally I'm not sure whether I'd recommend it.