Upon completion of the game, not only do you get to control Yorda and have different music, but her subtitles are now in English rather than in hieroglyphics.
Game Shark Codes
Master Code (Must Be On) EC87A648 143ACAF4
Low Enemy A.I. 1C818848 15F6E79D1C81884C 1456E7A51C8A3C70 15F6E79D1C8A3C74 1456E7A5
Save Anywhere [Note] 0CBF92F6 1456B10C4CF6B274 1456E7AE
Press Select to Walk on Air DC938022 142ED6F71C899850 15F6E79D1C899854 1456E7A5
Press Select + X to Return to Normal Walk DC934022 142ED6F71C899850 39A1B0951C899854 91D38BAD
Note: Pause the game and press L2 to save anywhere. When you load the game, you must sit on the couch once so the save menu appears. After that you can save anywhere, even without Yorda.