[Hakulyte]

10th player in the original StarCraft 2 to get every achievements in the world. (that's probably the most insane race I've been part of)

2nd Assassin in a Ragnarok Online server to reach max level which was done in around 3 years playing around 12 hours/day which was a ridiculous commitment. (#1 got it like 2 days before me)

Won a local tournament of Unreal Tournament 2004 against a pool of players that included the #3 1v1 player in Québec. (The tournament wasn't 1v1, but we still had to deal with a guy that could kill 20 players in a row before losing 1 life.)

Found a collision glitch that allowed skips in Zelda: Link's Awakening before there was any site with those lists. (pushing pushable blocks while standing in the corner of the block at a certain angle so the game can't tell which direction you're trying to push. It would allow you to push a block on top of another block which was clearly not intended. It's hilariously exploitable in Eagle Tower, the 7th dungeon. I didn't even find the intended path of that dungeon up to this day, only the weird glitchy route)

There's probably other things, but it's not on the same level I feel. e.g: getting Perfect:1 in the N64 Perfect Dark's training simulator which takes months to farm (and that's if you know what you're doing). Every nadeo medals on Trackmania United & Forever. Mostly time commitment stuff over skills.