The 1.2 patch for Crysis Warhead was released on February 5, 2009. The patch focuses on fixing and adding new features to the single-player portion of the game. It makes a few fixes and tweaks and adds 64-bit executables for Windows XP x64 and Windows Vista 64-bit. To access the new 64-bit executables, find the new shortcut in the Crysis Warhead program group in XP, and in Vista right-click the Crysis Warhead icon and switch to 64-bit mode.

Crysis Warhead puts players in the role of an elite operative codenamed Psycho who is on a mission to track down a North Korean warhead on a tropical island. The story takes place in the same time and place of the original Crysis, filling in the events of what happened on the other side of the island. Psycho's story eventually intertwines with the plot of Crysis as you experience events from Psycho's perspective and cross paths with Crysis protagonist Nomand.

Gameplay-wise, Crysis Warhead expands on the action-based open-ended first-person shooter style of the original Crysis. Psycho, like Nomad, has a nanosuit which gives him superhuman strength and stamina. His suit can go into multiple modes allowing him to take hits, be agile and fast, take on immense phsyical strength or even go completely invisible. Warhead adds a number of new customizable weapons and vehicles. It comes packed with a separate multiplayer mode, Crysis Wars.