Costumes
"God of War: Chains of Olympus" features several costumes that players can unlock in the game. The McKratos costume enhances the attacking ability of the main character, Kratos. To get the McKratos costume, players must finish each of the five missions of the Challenge of Hades, a group of five new missions that can be earned by beating the game on any level of difficulty. Defeating the game in God mode, the highest level of play, will unveil the Mime of War costume, which helps increase a player's red orbs. The Spud of War costume helps players with their magic and can only be earned by beating the game on any level of difficulty.
God Mode
God mode, the most difficult level of play in the game, is only available to players who have beaten the game on another difficulty setting. Costumes do not show up in God mode until a player has beaten the game on God mode. The costumes are then available to players who play through God mode a second time.
Treasures
"God of War: Chains of Olympus" features a Treasures section that has secret levels and items players can earn, including the Challenge of Hades. Many characters in the game have associated concept art that players can also earn by finishing the game. Beating the game offers other perks as well, such as in-game movies and a feature called "Inside Ready at Dawn Studios." Another feature, "Making of Attica," becomes available only after beating Chains of Olympus on God mode, as do the game's outtakes concept art. After finishing the Challenge of Hades missions, players will unlock environment concept art and the game's lost levels. The lost levels feature fights and puzzles that do not appear anywhere else in the game.