Beat the game and save your data at the end of the credits. You can now start a new game on Hard Mode from the Main Menu.

Beat the game and save your game at the end of the credits. You can now enter Time Attack Mode by pressing the Circle Button to pray in front of a Colossus statue. By beating the Colossus under the required time limit in Time Attack mode, you can unlock new weapons and items. Read below for the rewards, in the order that you'll receive them.

Whistling Arrow ... Distracts a Colossus when you fire it.
Cloak of Force ... Increases the amount of damage your sword will do to a Colossus.
Mask of Strength ... Allows you to inflict deeper wounds into a Colossus.
Lizard Detection Stone ... Allows you to find the white tailed lizards throughout the land.
Fruit Tree Map ... Allows you to find the Fruit Trees around the map more easily.
Mask of Power ... Allows you to inflict more grievous wounds on a Colossus.
Cloak of Deception ... Makes you invisible to the Colossus.
Flash Arrow ... Explodes and can damage a Colossus without hitting its vitals.

Hard Time Attack Mode unlocks more options and this version of Time Attack is unlocked after clearing the Story Mode on Hard difficulty.

Harpoon of Thunder ... A new Colossus-whacking weapon.
Sword Of The Sun ... Allows the light beacon to operate even in patches of shadow.
Fruit Tree Map ... Identical to the cheat earned in Normal Time Attack.
Shaman Cloak ... Hero's defenses increased and he takes less damage.
Lizard Detection Stone ... Identical to the cheat unlocked in Normal Time Attack.
Shaman Mask ... Increases the hero's defence. This cheat's effects stacks with the Shaman's Cloak. Think Red Ring from Legend of Zelda.
Cloth of Desperation ... Hand-made parachute allows for soft landings. Similar to the gliding ability in Sly Cooper.
Queen's Sword ... An ICO easter egg. It has the side benefit of killing a Colossus with great ease, but without the nuclear fallout.

 

You must first get all the items in Normal Time Attack mode. Then hold down Square button at title screen.

You must first get all the items in Hard Time Attack mode. Then hold down Circle button at title screen.

Each time you beat a Colossus, your strength meter will increase. If you make it large enough, you'll be able to climb up the back of the temple you first start in. Up top, you'll find the courtyard from the end of the game and the bridge that you entered on. There isn't much to do here, but you will find some fruit in the trees. Shoot it down and eat it and you'll decrease your health and strength meters. The only reason you might want to do this is if your strength meter is getting so big it is taking up too much of your field of view.

To get there, run around behind your starting shrine. There is a patch of ivy that you can climb up. When you're climbing, jumping in a diagonal or sideways direction causes your strength meter to decrease less than a straight climb or jump. Make your way up and then around the scaffolding up to the top.

When galloping, simultaneously press down on the left analog stick and the X button.

When galloping, simultaneously, and quickly, press down on the left analog stick and the X button twice. Argo wil stop and turn around to run the other way.

Press and hold R1 and X while galloping.

Wander can grab onto the various flying fauna in the world. Simply follow one on the horse and when the bird flies low, press JUMP to vault off the horse and hold GRAB. If your aim is true, Wander hangs onto the bird for as long as your grip meter holds out.

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.

1. Foxtrot-5
2. Foxtrot-3
3. Echo-2
4. Golf-5
5. Hotel-4
6. Delta-6
7. Delta-1
8. Golf-6
9. Delta-3
10. Bravo-4
11. Foxtrot-1
12. Golf-2
13. Echo-6
14. Charlie-2
15. Golf-1
16. Foxtrot-8

During any cinematic the right analog stick can pitch and yaw the view. R1 and R2 zooms in and out. Now you can get pictures of those naughty bits.