Eragon Codes -

Achievements
Complete each achievement to get the allotted gamerscore:

Carvahall: Hard (30) - You have made it through the Carvahall level on Hard.
Carvahall: Normal (20) - You have made it through the Carvahall level on Normal.
Daret Bridge: Hard (30) - You have made it through the Daret Bridge level on Hard.
Daret Bridge: Normal (20) - You have made it through the Daret Bridge level on Normal.
Daret Docks: Hard (30) - You have made it through the Daret Docks level on Hard.
Daret Docks: Normal (20) - You have made it through the Daret Docks level on Normal.
Daret Town: Hard (30) - You have made it through the Daret Town level on Hard.
Daret Town: Normal (20) - You have made it through the Daret Town level on Normal.
Gil'ead City: Hard (30) - You have made it through the Gli'ead City level on Hard.
Gil'ead City: Normal (20) - You have made it through the Gli'ead City level on Normal.
Gil'ead Keep: Hard (30) - You have made it through the Gil'ead Keep level on Hard.
Gil'ead Keep: Normal (20) - You have made it through the Gil'ead Keep level on Normal.
Ra'zac Chase: Hard (30) - You have beaten the Ra'zac Chase level on Hard.
Ra'zac Chase: Normal (20) - You have beaten the Ra'zac Chase level on Normal.
The Spine Mountains: Hard (30) - You have made it through the Spine Mountains level on Hard.
The Spine Mountains: Normal (20) - You have made it through the Spine Mountains level on Normal.
Trapped: Hard (30) - You have beaten the Trapped! level on Hard.
Trapped: Normal (20) - You have beaten the Trapped! level on Normal.

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