Successfully complete the indicated task to unlock the treasure:

Challenge Of Hades   - Successfully complete the game on any difficulty
Character Concept Art- Successfully complete the game on any difficulty
Environments Concept - Successfully complete the Challenge Of Hades
God Mode             - Successfully complete the game on any difficulty
In-Game Movies       - Successfully complete the game on any difficulty
Making Of Attica     - Successfully complete the game on the God difficulty
McKratos costume     - Successfully complete the Challenge Of Hades
Mime Of War costume  - Successfully complete the game on the God difficulty
Outtakes Concept Art - Successfully complete the game on the God difficulty
Spud Of War costume  - Successfully complete the game on any difficulty
The Lost Levels      - Successfully complete the Challenge Of Hades