Upon completing the game once, you will unlock Hard difficulty. Enemies will hit harder and you will lose your Runner's Vision, meaning objects will no longer be highlighted red to indicate a viable freerunning path. Due to the increased damage that you'll take, it is recommended that when given the chance, you should disarm enemies and use their weapons against them, as trying to run past packs in tight areas can easily result in your death. Complete all Chapters and the Prologue for this trophy.
NOTE: Some people have reported this trophy not unlocking when simply playing the chapters through Chapter Select. Because of this, it is recommended you start a new game on Hard difficulty, as opposed to just going through each mission via Chapter Select.