Harder Difficulty
Description: Unlock harder difficulties for subsequent playthroughs of the game,
How to unlock: Try beating each stage once through in their entirety. Now, when you play the stages again, you'll have the option of playing on harder difficulties.

River Belle
Description: unlock River Belle
How to unlock: Complete the first story mode. After completing Mt. Vaal for the second time, you can go to River Belle.

New Game++
How to unlock: beat New Game+ in is entirety.

Home
Description: unlock an area called Home, where you can communicate with characters from Story Mode
How to unlock: complete Story Mode once through in its entirety.

New Game+
Description: Unlock a New Game+
How to unlock: Beat the game once through and start a new game using your old save file.