[bystronic]

è in inglese ma puoi sempre tradurtelo con Google:

Locate the difficulty files in your Crysis installation folder (ie: C:\Program Files\Electronic Arts\Crytek\Crysis\Game\Config). These files are called diff_easy.cfg, diff_normal.cfg, diff_hard.cfg and diff_bauer.cfg. Open the file (with Notepad) that corresponds to the difficulty level you are playing. Add the following line to the end of the file and save it:

g_godMode = 1

Now, when playing your health will still decrease but you will not die. Instead, your health and armor will automatically replenish when your health reaches 0.

Additional Cheats
Using the same method as above, add the following lines to the end of your config file for the corresponding effect:

Code: Result:
i_unlimitedammo = 1 Unlimited Ammo
ai_IgnorePlayer = 1 Enemies Ignore You
i_noweaponlimit = 1 Carry Unlimited Number of Weapons