RC pro am in the big bathroom with 4 stalls, passing the link cable under the dividers. Best way to skip class ever. Only ever managed 4 players a couple times but it was amazing.
IIRC you only needed like one copy of the game, too??
Each player needed a copy of the game. Game Boy Advance had a bootloader that could receive data to run a multiplayer game with no cartridge.
Found this list: https://www.mygamer.com/gba-single-pak-linking-games/