Sneak up on Santa Claus before he takes off and he'll give you a few presents.
At the top right of the map on level 1, there is a hidden island with a load of preasents for the taking. You will need rocket skates, an inner-tube or icarus wings to get there.
During game play pause the game and press Up + A + B + C at the same time. Then press right + A at the same time. Then press down+B at the same time and press left + C at the same time. Then unpause.
On Level 1, on the bottom left side, there is a small hole that leads to level 0, which has hula dancers in a tub and a lemomade man who gives you another life.
To get across the water, use any type of item that does that (tube, rockets ect).