Pokémon Quetzal (V8.4)

It is an industry-leading GBA ROM hack that transforms the classic Pokémon Emerald experience into a modern, multiplayer-focused adventure. This is the first GBA project to implement a seamless 1-4 player CO-OP system, allowing you to explore Hoenn, battle NPCs, and trade with friends in real-time as if it were an MMO. The game features a staggering roster of every Pokémon from Generations 1 to 9, including Alolan, Galarian, Hisuian, and even the brand-new Legends Z-A Mega Evolutions. With a unique system that allows up to six Pokémon to follow you at once, 113 playable characters, and every modern battle gimmick (Megas, Z-Moves, Dynamax, and Tera), this is arguably the most feature-complete Emerald hack ever made.