Hacking the Game Boy’s Multiplayer Randomizer Creates the Perfect Version of Tetris

Do you remember the thrill of getting two straight line pieces in a row while playing Game Boy Tetris? It made you feel like running out and buying a lottery ticket. Now imagine the feeling if Tetris served up a never-ending buffet of just straight line pieces—this could be the greatest video game hack of all time.

Twitter’s ‘stacksmashing’ first came to our attention after reverse-engineering and hacking Nintendo’s Game & Watch revival a day before it was officially released, and then quickly figuring out how to get it to natively play other Nintendo games including The Legend of Zelda and Pokémon. More recently he’s turned his attention to hacking the original Game Boy, and even finding a way to turn the handheld into a Bitcoin mining device—albeit a very, very slow one.

Free money is cool, but stacksmashing’s latest hack realizes a fantasy that anyone who’s ever played Tetris has secretly harbored. But instead of modifying the game cart itself, the hack cleverly leverages Game Boy Tetris’ multiplayer mode which relied on the Game Link Cable accessory to physically link two consoles together. (The Game Boy was released long before Bluetooth and wifi facilitated easy and fast wireless connectivity.)

After reverse-engineering how two Game Boys communicate over the Game Link Cable by sniffing the traffic being passed back and forth, he discovered that the Game Boy that initiated multiplayer Tetris sent over a copy of all the randomized pieces that were to be dropped ensuring each player had the same gameplay experience. Using custom hardware that was similar to what allowed him to mine Bitcoin on a Game Boy, including a Raspberry Pi Pico, he was able to write a program that sent only straight line tetrominoes (the official name for the assortment of Tetris shapes) to a Game Boy in multiplayer Tetris mode, making it impossibly easy to play the most satisfying game of Tetris imaginable.

Eventually, stacksmashing hopes to leverage his newfound understanding of how the Game Link Cable works and his custom PCB boards that allow it to connect to a standard USB port to create an adapter allowing multiplayer Game Boy titles to be played over the internet with anyone on earth, instead of someone sitting a couple of feet away from you.