Unlock everything:

Start a new game with the name Golf_Gone_Wild.

Super skill:

During play, hold R and press White, Back, White, Black, Back. You will hit balls perfectly.

Beating Token:

During play, hold R and press Black, X, Black, Black, X. This only works if you do not have any Beating Tokens.

No wind:

During play, hold R and press Up, Left, Down, Right, Up, Left, Down, Right, X, X.

Taunting:

In a two-player game, press A when the other player is swinging to taunt them.

Fifth Outfit:

At the Character Select screen, hold the L trigger and press Y, Y, White, Y, Black, Y.

Change Ball Size:

To increase the size of the ball, hold down the R trigger and press Up, Up, Up, Down. To make the ball smaller hold the R trigger and press Down, Down, Down, Up.