First of all, I love these little dudes. They've got a lot of character and a unique design. My only suggestion here is on your color count. Right now, you have 11 colors, which is wildly high for a sprite that small, imho, and not at all visable unless you zoom in about eight times. You could up the contrast to make it more visable, but I also think you could easily pull this off with 3 colors total: Your darkest shade, your yellow, and one shade of dark+yellow. Other than that, they're pretty neat little guys and I kind of want to see them bopping after me in a platformer.
Спасибо большое