In God of War: Ghost of Sparta for the PSP, you can unlock several different costumes for use in extra playthroughs of the game.
Deimos Costume – Beat the game on any difficulty
Ghost of Sparta Costume – Beat the game on God Mode
God Armor Costume – Beat the game on any difficulty
Grave Digger Costume – Beat The Temple of Zeus
Robotos Costume – Purchase in The Temple of Zeus