Let take a look at the character.
There is nice shading in the body and an overall consistent colour scheme.
The most striking elements are the hat, which looks too flat and the limbs, as they are very straight.
The proportions of the face make him look a little boring, due to being elongated with a lot of space between the eyes and the mouth.
Creating a triangle from both eyes to the center of the mouth. The smaller the height of the triangle the cuter the character appears.