> The game runs on a Nintendo GameCube, a 24-year-old console with a 485 MHz PowerPC processor, 24MB of RAM, and absolutely no internet connectivity.

In fact, Nintendo did release an official add-on called the Broadband Adapter, which plugged into the bottom expansion port and provided an Ethernet jack. Only a handful of games supported it, one was Phantasy Star Online. I also used it to stream games/roms from a PC. This worked by exploiting a memory vulnerability in Phantasy Star Online to load arbitrary code over the network, though with slower load times compared to running from disc.

This is mentioned in the article:

"What About the GameCube Broadband Adapter?

Yes, the GameCube had an official Broadband Adapter (BBA). But Animal Crossing shipped without networking primitives, sockets, or any game-layer protocol to use it. Using the BBA here would have required building a tiny networking stack and patching the game to call it. That means: hooking engine callsites, scheduling async I/O, and handling retries/timeouts, all inside a codebase that never expected the network to exist."