To use the Candipults, press Y when near them. Rotate them with the Analog-stick and press Y again to set it. Aim all the candy balls into the giant bowl to complete the level.
Getting Augustus out of the pipe
Get two Oompa-Loompas, then find the stairs. You will find some machines. Order the Oompa-Loompas to work. Augustus should then blow up into the tube.