Unlock God Mode:
Beat the game on any difficulty
Unlock Credits:
Beat the game on any difficulty
Unlock Deleted Levels:
Beat the game on any difficulty
Unlock 'In-Game Movies'
Beat the game on any difficulty
Unlock 'Heroic Possibilities':
Beat the game on any difficulty
Unlock 'Monsters of Myth':
Beat the game on any difficulty
Unlock 'Challenge of the Gods':
Beat the game on any difficulty
Unlock 'The Birth of the Beast'
Beat the game on any difficulty
Unlock 'Visions of Ancient Greece'
Beat the game on any difficulty
Unlock 'A Secret Revealed':
Beat the game on God Mode difficulty
Unlock 'The Fate of the Titans'
Beat the game on God Mode difficulty
Unlock 'Character Graveyard'
Beat the game on any difficulty