All characters, cutscenes, and 9999 shop points:
At the title screen, hold L R and then press UP, DOWN, RIGHT, LEFT, X, B, Y, A.
Hidden modes:
There are five gameplay modes that are hidden: Non-Stop Fever, Excavation, Giant Puyo, Ice block, and Spinner. To unlock these modes, repeatedly buy the item in the fourth tab of the shop until you unlock one of these modes. You must unlock all five individually this way.