As the original NES game explains in the opening section: to depict Kirby you just draw a circle, some nubs for arms, shoes for feet, and then add a face. You can project anything you want into that because the face could be anybody’s. It’s interesting that the original game and several others have stressed and even encouraged people to draw Kirby. It taps into other aspects of people’s imagination because they can recreate Kirby however they like outside of the game. A quick doodle of Kirby looks just as much like the little pink ball as an expert rendition, there is no skill barrier to drawing him. Contrast that to something like Mario or Link, which people still love to draw, but can potentially be disappointed when their work doesn’t look like the original. Being able to draw Kirby easily removes a barrier to the avatar so that people can feel a greater sense of authority and control over it.
via popmatters.com