Eragon Codes -

Fury mode:
Press to pause your game, then hold + and press (x2), (x2).

How to beat Durza:

As you start the final battle with Durza, hold + and shoot Fire Arrows at him on his demonic steed. When he fires purple missiles at you, release and keep held. Press rapidly, and Eragon will deflect the missiles back at Durza. However, when the Shade fires Fire Balls, you cannot deflect them. Just dodge them. Continue this until he is dead. There is a secret egg in this level, but is extremely difficult to find. Look for the telltale blue dot on the screen.