But all the walls in the levels are made of mirrors, you can only see the images of things on the mirrors...Learn to play with this particularity in mind.
In some levels, the King is present because he wants the Candy for his own. He shoots avocados that can kill you. The closer you get to the Candy, the faster the King shoots.
In the last levels, you can get a power allowing you to fire a laser that can reflect on the mirrors and destroy everything it meets.