Right click and create the following new strings and set each with a value
of '1' for Enabled, '0' for disabled:
PlayerInvulnerable - Unlimited Health For You NPC
Invulnerable - Unlimited Health For Allied Friends
FullWeaponEquip - Get All Weapons
DoInGameLoadSave - Load Game and Save Game options appear in the options menu
Cheats will only work after a new level is loaded (loading savegame does NOT count).
Don't use Load as it doesn't always work properly (go back to the main menu
instead), but Save should be fine, except you don't get a save-point icon and
the game will be called "TestGameName".