Castlevania: Curse of Darkness - Boss Rush mode

Crazy mode:
Successfully complete the game. Then, start a new game and enter "@CRAZY" as a name to play on the Crazy difficulty setting.

Easter Island statue:
Have a saved game file from Castlevania: Lament Of Innocence on your memory card.

Moebius Brooch:
Successfully complete the game on the Crazy difficulty setting to unlock the Moebius Brooch at the shop. When this item is equipped it allows you to do special moves without using hearts.

Play as Trevor Belmont:
Successfully complete the game. Then, start a new game and enter "@TREVOR" as a name to play as Trevor Belmont. Trevor cannot craft items or use innocent devils.

Sound mode:
Successfully complete Boss Rush mode to unlock the music box in the warp room. This item allows access to the "Sound Mode" option to play various music from the game.