All characters and courses

Remove all memory cards from the PlayStation. Then on controller two, when the screen flashes just before the Hot Shots logo appears during the opening sequence, hold L1 + L2 + R1 + R2. Keep those buttons held, and press Up(2), Down, Up, Left, Right(2), Left, Up(2), Down, Up, Left, Right(2), Left on controller two while the Hot Shots logo is in motion. If you entered the code correctly, you will hear the sound of a wood driver.

Left or right-handed golfer

At the character selection screen, highlight a golfer, then hold L1 and press X.

Reversed courses

At the course selection screen, highlight a course, then hold L1 + L2 and press X.

In-game reset

While playing the game, press L1 + L2 + R1 + R2 + Select + Start.