In any level with a waterfall, stand underneath the waterfall and repeatedly tap one of the following buttons to immediately exit the level and enter a hidden minigame stage.
Pause the game and press X + Y.
You must first get the power up that allows you to swing from purple lums. Then go back to the first level and enter the part where you have to climb. When you reach the top, swing by the lum and you will be able to get to the village. Here you can place crystals to unlock extra features in the game.
Press A, B, X, Y, X, Y in Morb_20.
Press Up, X, Y, Down, Y, X, Left, Right.