Nice work! :D
You've done the shape and poportions quite well but I think you should work on colours a bit more. Placing a blue character against a blue background isn't a very good choice because it makes it hard to see the character. You should try adding more scenery instead of a simple background like you have done. The head seems too big for the body. The font/text doesn't look very good, it's hard to read and doesn't fit the style of the character. You should draw your text next time instead of using the text tool. I think the colours you've used are too bright and you should reduce the saturation a bit. The shading is done quite well, not perfectly, but you'll definently improve with practice. I look forward to seeing your other work :)