So, basically, for much of Tetris's history, people believed level 29 was the "last" level of Tetris, as the speed of the blocks would get so high that no human could do anything but lose; the blocks would go so fast that human hands physically could not control them. However, Tetris does not get any faster beyond that point, so if you're capable of playing level 29, you're capable of playing hypothetically infinitely.
Except Tetris, the original version for the NES, is not a hypothetical. It's a physical object, an item you can touch and hold, and it has limits. Many classic arcade-style video games have honest-to-god killscreens, where the game breaks so badly that it becomes completely unplayable. Pac-Man, famously, has a killscreen that garbles half of the playing field and doesn't spawn enough dots for the level to ever end. Tetris was assumed to be no exception, but because of the presumed-impossible difficulty of level 29, the community considered that to be Tetris's killscreen, and all high-leveled Tetris play centered around level 29 being the absolute end of your run, no matter what.
But, and if you've heard literally anything about people getting insanely good at retro games, you'll know what comes next. Of course, someone figures out how to control the game past level 29. In 2011, Thor Aackerlund discovered a technique now known as "hypertapping" (which is exactly what it sounds like, tapping very very fast) - and became the first person to play level 30.
But hypertapping wasn't enough. It was still stupidly difficult to get to, let alone past, level 30. Then this guy named Cheez shows up and finds that using an even more absurd technique, called "Rolling", which was even faster than hypertapping. People weren't just hitting level 30, but then 40, then 50, and then all the way into the 90s. Since all post-29 levels have the exact same speed, once they mastered rolling, they were pretty much good to play forever.
With levels 29+ conquered, now players could face the real killscreen of Tetris. A Tetris-playing AI got the first crash, but since it was playing a very slightly modified version (to show a larger score number, because the vanilla score counter didn't have enough digits), it only kinda-sorted counted. So the community picked apart the game's code to find where the game could hypothetically crash while completely unmodified - and found the current human record was not that far off.
So the entire community fucking scrambles to be the first person to crash Tetris, but then were confounded by another technically-not-game-ending-but-still-pretty-much-impossible-for-a-human bug; after level 138, the game stops choosing the colors for the blocks from where it's supposed to, leading it to display some truly heinously color palettes. Most of them are just ugly, but a few make the blocks you're placing next to invisible. (This was actually known about before the AI even crashed the game, and part of the reason the AI could get so much further than humans; it didn't need to visually see the blocks.)
Just next to invisible, though. You could still sorta see most of the blocks, and when you pass the level, the game pulls a new color palette, so if you can tough it out long enough to get 10 lines, you're probably gonna be able to continue your game for a while after that. It's annoying as hell, but not impossible. So, of course, the runners start getting past them and brushing up against the crashable levels.
And by runners, I mostly mean a 13 year old boy who goes by the online handle Blue Scuti. He'd skyrocketed into fame in the Tetris community relatively recently by achieving scores and levels that most adults couldn't even dream of, so of course he was among the first people to get past both impossible-palette levels, and he was able to keep going.
The game doesn't always crash in one specific spot, though. It just starts having a chance to crash after a certain point. You might have to perform some specific actions in specific windows of time to get it to crash on purpose, and it's much more likely that you'll lose control and lose your run before you achieve that goal.
Blue Scuti missed the first crash opportunity in his run. He was the first person to get that far at all, so it'd be a record regardless, but he was determined to win. He somehow keeps his cool, despite being a literal child with thousands of eyes on him (this was streamed on Twitch, of course), and never loses control of his stack, all the way until he reaches the next crash opportunity all the way on level 157.
And he fucking does it. He gets a single line clear in the middle of level 157 and the game just stops. It completely crashed. A 13 year old boy nicknamed Blue Scuti is the first human being in history to crash Tetris in this way. He is the first person ever to see Tetris's real killscreen. This game is over twice his age, and he is the first to kill it dead.
(if you want more detail, I learned basically all of the above from this video by aGameScout, please watch it!!)
