What are your steam hardest games ?

Cs:go, it's so difficult for me to load up the game up knowing how much sweat and salt is waiting for me in that hellhole. Great game. #LostRank3TimesDueToInactivity

try this juan

Quite Subjective, some that people have mentioned I found easy as I'm sure some on this list people will have found easy, games that I found difficult are....

Shogun 2 on Legendary
Binding of Isaac: Rebirth as The Lost(1 hit death)
Crusader Kings/Europa Universalis, grand strategies that take 100 hours just to learn how to play, I don't necessarily believe its "hard" but its certainly hard to just "learn" the game.
Super Meat Boy, infuriating, especially for a completionist like me who wants to get A+ on every map.
SEGA Classics Some of those old school games man...fuck Altered Beast and fuck that Golden Bull at the end.
Murasaki Bullet Hell, "easy" to finish, then you realise, you haven't finished at all and there's all sorts of hidden levels and extra characters.
Darkest Dungeon Achievement whore here, fuck Dismas and fuck Reynould(whatever they're called), determined to die at level 5/6 at the end game robbing me of an achievement of just getting them to the last Darkest Dungeon fight.
Civ Series on the top difficulties its very difficult, I struggle to win on the lower difficulties and I've played a lot of Civ since Civ 2.
X-Com/X-Com 2 Hardcore Impossible difficulty....1 mission goes wrong and it could signal the end for your entire save.

Super Meat Boy, FTL: Faster Than Light & Risk of Rain.