These two games have many of the same features, but one of these games is better. Here is a comparsion showing the similarites and differances of these games.
Cystal Chronicles and Four Sowrds both need 2-4 Game Boy Game Cube link cables.
The way Cystal Chronicles uses multiplayer may be a bit diffcult and dosen't give you much freedom with the fog around while the way Four Sowrds Adventures uses multiplayer gives you more freedom and gives you more multiplayer minigames like shadow battle and Tingle's tower even though Cystal Chronicles lets you play Blazin' Caravans.
The way single player is used in Four Sowrds Adventures is top notch and lets you control four Links at once by using formations and lets you play with a Game Boy Advance even with on link cable while the way Crystal Chronicles uses single player mode is by letting you creating eight party members and letting you use olny one, but Mog the moogle helps you in your adventure by carrying the Crystal Chalice and casting spells at rare times.