Unlock Gandalf's Level 4 Attacks and Abilities:
Go to the pause screen and hold the Left CTRL, ALT, and SHIFT keys.
Then input the numeric sequence: 6, 8, 7, 4 on the number pad (while
holding the other buttons). Then release the buttons. You will hear
a metallic clink sound to confirm your cheat was accepted.
Unlock Four-Hit Combo For Aragorn:
Pause the game and enter 8, 7, 6, 9.
While in the game, press ESC and hold LSHIFT, LCNTRL and LALT, and press in the key pad:
5964 - perfect mode
7754 - restore health
6869 - always devasting
8967 - all upgrades
7795 - infinite missiles
7578 - invulnerable
9587 - targeting indicator mode