Glad you started and did some animations! I regret not animating while I was first learning how to pixel. You wouldn't get great feedback on Pixel Joint because it's intended to display the piece, critique isn't the purpose of the website, whereas on Pixelation, it's developed for progression with art. If you are looking for critiques through Pixel Joint, their forum has a WIP section. Anyway with all of that said I think the biggest issue with these sprites is the shading. Let the shading define their form! Right now you're sprites don't have enough definition to them. You should start by really thinking of exactly what you want these characters to look like before you draw them (or while you are, but before is always better
). I do like the back view of the head on your ninja sprite, except for by making his butt that bright it looks as if he is sticking it out while walking. On a sprite of that size defining the butt that much isn't necessary.
