Unlock hidden characters
Complete Story mode at hard difficulty to unlock a hidden character.
Completion Hidden character
1st Hanged Man
2nd Express
3rd Fortune

Unlock the Master’s Closet
During game, catch all 10 white witches. Raison will be brought back to life and he will open the closet for you. The closet leads to a dungeon that contains 50 floors and a boss on every tenth floor. 

“All Clear” bonus
Clear all colors from the Self-Challenge mode playing field to receive the All Clear bonus. Alternately, leave a color and grab the remaining drops before the next line descends.