Shadow of the Colossus Cheats
Get all the items in Normal Time Attack mode. Then hold down Square button at title screen.
Get all the items in Hard Time Attack mode. Then hold down Circle button at title screen.
Finish the game and then save after the credits are over. When you start the game again, the Hard Mode will be in the main menu.
While galloping, hold down on the left analog stick and the X button at the same time.
While galloping hold down on the left analog stick and the tap X button twice. You have to do this one fast.
Stand While Riding
While galloping press hold R1 and X.
While on your horse, get behind a low-flying bird. Jump off the horse while holding the grab button. If you've done it right, you've got yourself a bird.
If you return to a Colossus previously defeated, only large piles of rocks signify their remains. Approach and use the ruins as you would a save shrine to fight the colossus again in a replay (not time challenge) battle.