Eragon

Unlock Hidden Level: Throne Room
Collect all of the secret eggs in the game on any difficulty level.

Secret egg bonuses:
Collect the indicated amount of hidden eggs in the game to
unlock different bonuses:

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