Crysis Warhead updates and refines the gameplay of the original game through a sidestory plot involving Psycho, one of previous protagonist Nomad's allies. The game is a parallel story that follows Sergeant Michael "Psycho" Sykes, a character from the original Crysis, as he faces his own trials and challenges on the other side of the island during the time period of the first game. It features new fully customizable weapons, vehicles and enemies, along with new multiplayer content. It also showcases a new, enhanced and optimized version of CryEngine 2.