Four Swords is the first multiplayer Zelda game ever released. It was only playable with two or more players, and was a short game when compared to the rest of the series.
Princess Zelda has been kidnapped by Vaati, an evil being who was sealed inside the Four Sword. Link must take hold of the sword and chase down Vaati to save the princess. However, the sword splits the wielder into four, giving them four fighters instead of one. The four Links set off to save the princess from Vaati's clutches.
This game was the first to feature Vaati. It was merely an add-on to the Gameboy Advance port of A Link to the Past, but it is still considered canon by Nintendo and the fans. This is a test for the use of the revert function.