We all know Tetris. Or, at least, we think we do. But while the core concept of the game hasn’t changed over the years, the implementation of that concept has a surprisingly rich history, starting with the game’s original release in the West—for MS-DOS, in January 1988—and continuing right through to the bewildering assortment of versions available today. This history is explored in minute detail during the newest video from YouTuber Garrett “Acerola” Gunnell, who usually makes (excellent) content about graphics programming. This video is something different for his channel, and it’s both minutely detailed and impressively comprehensive. Watching this video is a strange experience in a personal sense because the version I played most was the original DOS version from the 1980s. I’ve devoted a few idle minutes to various versions in the decade since, but they all seems basically the same—which made sense, because the original was pretty much perfect on arrival. Wasn’t it? Nope, says Gunnell. And he’s right, too. Once he points out the flaws of the 1980s version, they seem glaring and inexplicable: you can’t rotate the block until it’s fallen a couple of rows, because the game won’t allow it to “collide” with the top of the screen. If you choose to drop the block currently in play, it’ll plummet straight to the bottom of the playfield (referred to as a “hard drop”. ) The UI kinda sucks. And so on.