"Goosebumps: The Masked Mutant's Devastation"
https://arch.b4k.dev/vg/thread/434774680/#q434838047
https://rentry.org/maskedmutant
A creepypasta posted on /exeg/ in June of 2023. I haven't read the story at the time of writing this, but skimming the page has led me to assume Clownfag wrote it judging from the general shape of the story's formatting. This story has been promoted a handful of times on this general as one of the best, but I won't hold that against it.
I was gonna do a play-by-play, but the story's pretty long and there's not that much to nitpick, so here's the summary:
>Guy was obsessed with Goosebumps as a kid. He was so obsessed with Goosebumps that his parents didn't let him use a computer because they were afraid that he would buy Goosebumps stuff by himself. Since he couldn't use a computer, he never got to play the Goosebumps PC games.
>As an adult, the guy works at an advertising firm. The firm worked in advertising the Jack Black Goosebumps film, which reignited the guy's interest in Goosebumps, so he buys one of the Goosebumps PC games, Attack of the Mutant (which is a real game and is a first-person adventure game like Realm of the Haunting, Normality, or a poor man's System Shock)
>The eBay copy of the game the guy got has a sticker advertising "Mutantmare Mode", a gamemode not documented anywhere online.
>Mutantmare Mode replaces all characters in the game with the game's main antagonist, the Masked Mutant, a shapeshifting supervillain, and modifies many puzzles to more heavily feature the Mutant.
>At the end of the game, when the Mutant is defeated, he says that he'll haunt the player's dreams and get his revenge.
>After beating the game, the narrator's computer is infected with malware that causes the Mutant's laughter to loudly play at random and prevents him from turning it off (he never tries unplugging it).
>The guy hears the Mutant's laughter constantly and fears for his life. The story ends with him pleading for help.

TBC