New costumes can be bought at the store. The first four are unlocked by playing the tournaments. To unlock the fifth costume, first defeat Louise in versus mode. Then, defeat Blue, Estelle, John, Kamala, Lin, Louise, Mitch, Spike, Stacy, T-Bone, Toni, and Zeus in versus mode again (when they appear in their fifth costume). The fifth costumes for the defeated players will then appear at the store.
Caddie Mel
Win the Friendship Open on the beginner difficulty setting to unlock Caddie Mel.
Caddie Sophie
Win the Wild West Cup on semi-pro difficulty setting to unlock Caddie Sophie.
In-game reset
Press L1 + R1 + L2 + R2 + Start + Select during game play.
Left-handed golfer
Press Start when selecting a golfer.
New characters
Defeat the following characters in versus mode to unlock them as playable characters: Blue, Estelle, John, Kamala, Lin, Louise, Mitch, Spike, Stacy, T-Bone, Toni, and Zeus.
Tournaments
National Championship: f7f&&&4amtAg
Louise in the Bagpipe Classic (National Tournament): JfNd3d7ddfDa