Unlockable: New Game Plus Mode
Complete the game and at the end--when prompted--save your game. Then, from the title screen, load your saved data to start a new game with everything you had when you beat the game.
Unlockable: Survival Mode
Complete the game on Normal difficulty to unlock "Survival Mode."
Unlockable: Weapon Select
Follow the same instructions for unlocking "New Game Plus." On the "Katana Select" menu, press L1 and R1 to equip swords to both hands.
