Crysis Hints

Locate the difficulty files in your Crysis installation folder (ie: C:Program FilesElectronic ArtsCrytekCrysisGameConfig). 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.

Unlimited Ammo
Using the same method as above, add the following line to the end of your config file:

i_unlimitedammo = 1

Your ammo will be frozen in the game.

NOTE: ALWAYS MAKE A BACKUP BEFORE OVERWRITING GAME FILES.

Enter console mode: Press the tilde key(~), then type in the following and hit return:

r_displayinfo = 1

Hit tilde(~) again to exit console mode and you will now see your frame rate and other info in the upper right corner on your screen.

Make sure you have the suit shortcuts option enabled on the keyboard settings, then you can double-tap the following keys to access the suit powers:

Jump (spacebar) = Strength
Sprint (shift) = Speed
Move Backwards (s) = Armor
Crouch (ctrl) = Cloak

Note: These keys are based on default keyboard settings.