After creating a new file, type in Golf_Gone_Wild as a name.

Unlock Extra Costumes

At the character selection screen, hold R and press Z, Y (4x), Z, Y.

Unlock Larger Ball

During a game, hold L and press Up (3x), Down.

Unlock Smaller Ball

During a game, hold L and press Down (3x), Up.

No Wind

During a game, hold L and press Up, Left, Down, Right, Up, Left, Down, Right, X, X.