Here is the full list of all 20 Prince of Persia: Warrior Within trophies - there are 2 bronze, 10 silver, 7 gold and 1 platinum.
Obtain all other trophies
Complete the game on Easy difficulty
Complete the game on Normal difficulty
Complete the game on Hard difficulty
Obtain the Secret Ending
Obtain all hidden artwork
Use all Time Powers at least once
Grab and throw 100 enemies
Decapitate 150 enemies
Reach the Island of Time
Get all life upgrades
Obtain the Water Sword
Kill 100 enemies using a dual weapon technique
Defeat the Giant Golem
Defeat the Griffin
Defeat the Empress - Normal Ending
Defeat the Dahaka - Secret Ending
Complete the game in any difficulty without dying
Play the game for 10 hours
Throw weapon at enemies 50 times