We've all played Tetris. But probably not like this.
The GIF above is taken from the semi-finals of this year's Classic Tetris World Championship. The annual tournament was first held during the filming of the Ecstasy of Order: The Tetris Masters documentary, and has been a part of the Portland Retro Gaming Expo since 2012.
It's about as classic as Tetris gets. Competitors play on the original 8-bit Nintendo cartridge, and players are allowed to bring their own controllers provided they are also original, unmodified NES controllers.
Because it's the original NES version, the game speed isn't as blistering fast as some of the crazy versions released in Japan. But those versions are typically something you play against yourself -- not something you'd usually play on stage in front of a crowd.
And don't think because it's Classic Tetris that this is somehow easy. Once the stage hits level 29, NES Tetris is basically unplayable for most; the pieces drop too fast for people to properly traverse their tetrominoes. Even TAS bots can have issues.
If you want to watch the semi-finals, the Twitch stream is embedded below. Multiplayer Tetris (even if it's not Battle Tetris) is pretty fun.