Raise/Lower Water:
At the "main menu" press and hold:
c-down or c-up
This will allow you to bring up or down a whirlpool of water. While still holding a button, the analog stick makes it possible to move the whirlpool.

Change Floor/Background:
After finishing the sixteen practice rounds goto the options menu. Choose the "floor" option and you will be allowed to alter the floor and background designs and colors.