Eragon - Unlock Fury Mode

Full health:
Press Start to pause game play, then hold LT RT LB RB and press X4, B2. Your health will go up to full. Repeat this as many time as desired.

Defeating Durza:
There are two stages to fighting the evil Shade. For the first stage he will teleport around, slashing at you with his claws and shooting streams of flame. He will charge up his fire attack. When he does, run up to him and press A or B to grab him in a "full nelson" move. Keep tapping A, B, X, and Y and Brom will come over and hit him with his sword, Zar'roc. The Shade will break free. Hit him with your sword when he gets close. Get him to half health and the second stage of the battle will begin. In the second stage he will continue to teleport around, but will also ditch the fire stream attack for another. He will float in the air with a large red bubble shield around him. Many scimitars will fly off the walls and will shoot through the air towards you. After they stop, run up and attack him.

As you start the final battle with Durza, hold R L and shoot Fire Arrows at him on his demonic steed. When he fires purple missiles at you, release R and keep L held. Press A 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.

Use the following trick when facing Durza at the final battle. You will have to fly Saphira while trying to defeat Durza on The Shadow of Tirani. To defeat him, shoot your magic arrows at Durza. After he says something similar to "You should have taken my offer boy", Press the L and prepare to press A to shoot back the dark magic. However, he may shoot fireballs. To dodge these, fly in circles when they get close to you. After awhile you will defeat him. There will be a scene with Durza throwing a spear at Eragon. He will somehow disappear and stab Durza through the heart. Durza will die and Ajihad will tell the rest.

Hidden egg bonuses:
Collect the hidden eggs found throughout the game to unlock the following bonuses.

1 egg: Ad for the Eragon and Eldest books
2 eggs: Edward John Speleers commentary
3 eggs: Design commentary
4 eggs: Art direction commentary
5 eggs: Birth Of A Game commentary
6 eggs: Concept art
7 eggs: Orchestra commentary
8 eggs: Saphira commentary
9 eggs: Sienna Guillory commentary
10 eggs: Character concept art
11 eggs: Concept art
12 eggs: Concept art
13 eggs: Robert Carlyle commentary
14 eggs: Sound Effects commentary
15 eggs: Garrett Hedlund commentary
16 eggs: Evolution Of Games commentary
17 eggs: Concept art
18 eggs: Throne Room bonus level

Achievements:
Complete the following 37 secret achievements to unlock Xbox Live Gamerscore points.

Daret Docks - Normal 20 points: Make it through the Daret Docks level on Normal.

Daret Docks - Hard 30 points: Make it through the Daret Docks level on Hard.

Gil'ead Keep - Normal 20 points: Make it through the Gil'ead Keep level on Normal.

Gil'ead Keep - Hard 30 points: Make it through the Gil'ead Keep level on Hard.

Trapped - Normal 20 points: Complete the Trapped level on Normal.

Trapped - Hard 30 points: Complete the Trapped level on Hard.

Ra'zac Chase - Normal 20 points: Complete the Ra'zac Chase level on Normal.

Ra'zac Chase - Hard 30 points: Complete the Ra'zac Chase level on Hard.

Daret Bridge - Normal 20 points: Make it through the Daret Bridge level on Normal.

Daret Bridge - Hard 30 points: Make it through the Daret Bridge level on Hard.

Daret Town - Normal 20 points: Make it through the Daret Town level on Normal.

Daret Town - Hard 30 points: Make it through the Daret Town level on Hard.

Carvahall - Normal 20 points: Make it through the Carvahall level on Normal.

Carvahall - Hard 30 points: Make it through the Carvahall level on Hard.

The Spine Mountains - Normal 20 points: Make it through the Spine Mountains level on Normal.

The Spine Mountains - Hard 30 points: Make it through the Spine Mountains level on Hard.

Gil'ead City - Normal 20 points: Make it through the Gil'ead City level on Normal.

Gil'ead City - Hard 30 points: Make it through the Gil'ead City level on Hard.

Durza's Fortress - Normal 20 points: Make it through the Durza's Fortress level on Normal.

Durza's Fortress - Hard 30 points: Make it through the Durza's Fortress level on Hard.

Flight From Gil'ead - Normal 20 points: You have beaten the Flight From Gil'ead level on Normal.

Flight From Gil'ead - Hard 30 points: You have beaten the Flight From Gil'ead level on Hard.

Ruins of Orthad - Normal 20 points: You have beaten the Ruins Of Orthad level on Normal.

Ruins of Orthad - Hard 30 points: You have beaten the Ruins Of Orthad level on Hard.

The Beor Mountains - Normal 20 points: Make it through the Beor Mountains level on Normal.

The Beor Mountains - Hard 30 points: Make it through the Beor Mountains level on Hard.

Urgal Encampment - Normal 20 points: Make it through the Urgal Encampment level on Normal.

Urgal Encampment - Hard 30 points: Make it through the Urgal Encampment level on Hard.

Misty Gorge - Normal 20 points: Make it through the Misty Gorge level on Normal.

Misty Gorge - Hard 30 points: Make it through the Misty Gorge level on Hard.

Urgal Attack - Normal 20 points: You have beaten the Urgal Attack level on Normal.

Urgal Attack - Hard 30 points: You have beaten the Urgal Attack level on Hard.

Defend the Varden - Normal 20 points: You have beaten the Defend The Varden level on Normal.

Defend the Varden - Hard 30 points: You have beaten the Defend The Varden level on Hard.

Final Battle - Normal 20 points: Make it through the Final Battle on Normal.

Final Battle - Hard 30 points: Make it through the Final Battle on Hard.

Explorer 100 points: Collect all the secret eggs.