All Fish Are Bass
Press Up, Up, Down, Left, Left, Right at the main menu. A sound will confirm correct code entry.
Debug Mode
At the Ubisoft (US/EU)/Starfish (JP) logo, press Select, Up, Down, A, Left, Start. A debug sound test screen will appear once the logo fades out. Start the game and either choose Quick Fish mode, or choose Tournament or Practice modes, then press Select and choose Cast to access the main debug menu, where quite a few things, such as the color and amount of lures, the lake to fish at, the weather, the player character, the time, and the temperature can be changed.