Korea Forgotten Conflict (PC)
CheatingDome.com
Various Codes
You can use these cheats when you are in "Help menu" (F1):
Infinite ammo - CTRL + M
Invisibility - CTRL + X
Immortality - CTRL + I
End of the mission - CTRL + H
Type this cheat when you are in the menu where you can choose the mission:
Access to all levels - HOSSANA