Crysis Cheats

Cheat list
Head to the difficulty files in your Crysis folder (for example: C:\Program Files\Electronic Arts\Crytek\Crysis\Game\Config). The four files you're looking for are titled diff_easy.cfg, diff_normal.cfg, diff_hard.cfg and diff_bauer.cfg. Open the file (using Notepad) of the difficulty level you are currently playing or wish to edit. Add the following line to the end of the file and save it:

God Mode - g_godMode = 1
No Target - ai_IgnorePlayer = 1
No Weapon Limit - i_noweaponlimit = 1
Unlimited Ammo - i_unlimitedammo = 1

You can also modify your suit stats. For example:
g_playerHealthValue = 400.0 g_player
SuitArmorModeHealthRegenTime = 0 g_player
SuitArmorModeHealthRegenTimeMoving = 0 g_player
SuitEnergyRechargeDelay = 0 g_player
SuitEnergyRechargeTimeArmor = 0 g_player
SuitEnergyRechargeTimeArmorMoving = 0 g_player
SuitEnergyRechargeTime = 0 g_player
SuitHealthRegenDelay = 0 g_player
SuitHealthRegenTime = 0 g_player
SuitHealthRegenTimeMoving = 0 g_suit
ArmorHealthValue = 400.0 g_suit
CloakEnergyDrainAdjuster = 0 g_suit
RecoilEnergyCost = 0 g_suit
SpeedEnergyConsumption = 0 g_suitSpeedMult = 2

After making all of your edits, save the file, load up a new game and see what you've edited!