A hacker added online multiplayer to the Game Boy version of Tetris

It works by connecting a custom adapter to the handheld's Game Link port.


Not that long ago, Nintendo gave the world a new spin on the battle royale genre with the addictive Tetris 99. If that game tickled your competitive instincts — and rekindled your love for frenzied block-stacking — then this new hack for the OG Tetris could be for you. A professional tinkerer has figured out a way to add online multiplayer to the Game Boy version of the iconic game from 1989.

Those old, or lucky, enough to have experienced the old-school Tetris may recall playing head-to-head with others using the handheld's Game Link Cable accessory. Well, Stacksmashing's hack basically uses a tricked-out USB adapter (which relies on a Raspberry Pi Pico and some level shifters) to connect to the Game Boy's link port to bring it online. As a result, two or more people can play against each other over the Internet from anywhere in the world. The hack also works with the wider Game Boy family, including the Game Boy Color, Game Boy Pocket and Game Boy Advance.

Needless to say, it requires a lot more behind-the-scenes effort to pull off. Firstly, Stacksmashing reverse-engineered the data from an actual link cable. To handle communications, the tinkerer created an open source software stack which includes a Python server and WebUSB frontend. This ultimately tricks the Game Boy into thinking it's still in a two player match when, in reality, multiple players can get involved with the web interface keeping tabs on your progress.