9. Slender: The Eight Pages (PC)
It might not have been the originator of the “incredibly basic horror experience which’ll be squeezed dry by streamers” subgenre, but it’s difficult to go against the sheer popularity of Slender: The Eight Pages, often just referred to as “Slender Man”.
The game is as simple as they come - collect eight items (the titular pages, seemingly ripped from a child’s notepad) whilst avoiding a relentless and unkillable pursuer. Yet, this simplicity is what made it so attractive to Let’s Players and casual PC gamers alike, and it spawned an absolute plethora of similarly-structured games in its wake.
When I originally played it, I saw the novelty - Slender Man evokes a better-dressed Pan’s Labyrinth “Pale Man”, and appears seemingly at random, which is neat for a quick wee trouser-browning. Yet, the longevity was always in question, and I had gotten everything out of it I wanted to in an hour.
But those darned YouTubers, man - those guys could not get enough of Slender - if the game was a cow and views its milk, that cow would look like a burst black-and-white balloon today.
A “Slender Cow”, if you will.