Tony Hawk's Pro Skater 3

Unlock all cheats
To unlock all the cheats, go into the options menu then open the cheats menu. Enter the cheat "backdoor" and the whole list of cheats will become available in the game. To access them, when playing, pause the game and go down to the cheats option in the pause menu. You can toggle cheats on and off by pressing X.

Perfect manual balance mode
To unlock the perfect manual balance mode, you must finish career mode seventeen times, completing all 54 goals and getting 3 gold medals.

Always special mode
To unlock always special mode, you have to finish career mode twelve times, completing all 54 goals and getting 3 gold medals.