Neat image.
Your AA is pretty good. You've got the concept down. You'll naturally improve as time goes on and you practice.
Biggest thing here for me, is that this pic of Teddy (never heard of 'em) lacks pixel merit and is therefore better off as a vector; the same thing will be accomplished plus the curves will be perfectly smooth and AA'ed.. Yes, it's a tired argument, and each his own. Still, glad you've taken up pixel art and enjoy it, but I have to question the style choice.
Also, it has 162 colors. With that many colors you could give him smooth gradient shading. Somehow, you lost control of your palette along the way - a primordial pixel fundamental.
PS. Welcome to Pix! Hope you find it useful and are able to contribute, too.