This looks great! Some really nice colours and a fun design. In terms of things that could be improved, that depends a bit on context. The only anatomical notes I might have are that the eyes are quite high, which makes things feel a bit off. It also makes it more difficult to read an expression on the character's face, and makes it slightly uncanny (which may be intentional). Rendering-wise, I think this is some nice, clean cel shading without getting bogged down in details, and the colour choices are really nice!