Unlockable: Dancing Jack
————————
Complete the game once.
Unlockable: Phantom Jack
————————
You have to get S Rank in all of the level and complete it to open the
secret chapter.
Unlockable: PJs Jack
——————–
Complete the game once.
Unlockable: Pumpkin King
————————
You have to beat spider boss.
Unlockable: Santa Jack
———————-
Defeat The Doctor.
Unlockable: Thespian Jack
————————-
Got Rank A in all levels.