Very nice sprites. It looks like a good transition from the smaller game size to something with more details. Though adding a little (more?) dithering might help the overall product. Taking a quick glance, I'm not sure you used any. Also, be careful of pillow-shading. For example, the 2nd row forward walking poses, around the lower part of his shirt, near where it folds over itself. The shadows there are a little thick and gives it a pillow feel. There is a similar bit with the forward standing pose. In contrast, the shading on the scarf in the forward standing pose is beautiful, and in general you did an amazing job on the shirt's shading (in every other pose, really).
The hair bounce also looks nice (but that is hard to tell until it has been put into an animation).
You might want to add a little darker shading to the 2nd walking-to-the-right pose. It isn't very clear which leg is behind which (one really has to look at the arms to know for sure). A little more shadows there would fix things right up.
On the two side-standing (3/4tth) posses, you might want to move his arm more towards the center of his body by a pixel or two. Or possibly a little more underarm shading would work too. As it is, it almost looks like his arms are attached behind his shoulder, than attached to it.
But almost all that is just nit-picking and pixel-pushing obsession. Very good work.
As a side note, if you have the means, I highly recommend switching to Photoshop or some such program as soon as possible, if for no other reason than Layers. Layers are your best friend. As in, best-friends-with-benefits.
