Well, you've got the basics. There's a bit more attention to the detail needed however. Your outline shouldn't be all black. For the lighter areas, they should use the darkest shade of, in this case, green or grey. Another thing, I'm not 100% sure on this, but by the looks of things, you've used the preset colours on paint to make this sprite. It's okay, but not recommended. It's better to use a custome palette. Make sure your joints are life-like, not rubber-like, as we see in the one visible leg. Keep trying~