The sprite suffers from all-black outlines, pillow-shading, unnecessary colors and, worst of all, terrible anatomy. The whole thing is very stiff and rigid altogether, and the pose makes zero sense. 90% of me says this begs for a redo. I think anatomy is something you'll need to work on if you want to become even remotely successful in the pixel-art world, or let alone art. Let's see, tutorials, tutorials... Oh. Right. That just takes daily practice. A bit tedious at times, but it pays off.
...My tablet's not working. In the meantime I'll work on an edit with the mouse but it'll probably take a while longer...
EDIT: Well, since you asked. Finally got my tablet working again--just needed new drivers.
Another one of these super-long guides again...
Part 1: Addressing various anatomy problems:
Due to Paint's inability to let me write so small and keep it legible, I've marked problem areas with numbers, and will explain what would normally be in place of the number.
_________
1. One leg longer than the other? Seems like it. Otherwise a pose like this would be impossible. Actually, why would he be crouching like this when tossing a basketball out of his hands? That would have been the last of my thoughts if I saw this and you didn't tell me.
2. Note lack of a neck, like the neck is pointed towards us, as it would be on a hunchback. The angle of the head, straight towards us, seems especially uncomfortable, to the point where it's almost impossible to take on a pose like this.
3. Where's the elbow joint? Even if an arm is straight, like this, there's still going to be a little bit of a bend, at least some definition... Actually looking back it seems bent in a way that's also technically impossible uncomfortable. Very uncomfortable.
4. The spine is unnaturally straight, and I have a feeling this accounts for most of the sprite's rigidity. However, just bending it back isn't going to solve all of your problems. If anything that'll just throw it even more off-balance. How are you going to solve this, you ask? Well...
Here I made a new frame to build on. It should help. If not...
Part 2 the sequel: Converting that into a sprite.
I start to build around the frame, then block in colors. Then I pick out a light-source (you can just go with flat color if you want) and block out lighter shades where the light hits. Then I scale it down, clean it up a bit, and out comes this tiny guy:
Ain't it cute. Keep in mind, you don't have to do it the way I did it. In fact I recommend you don't. Just something to learn from.
Also this version, where limbs furthest from us are darker. It's a bit more readable, IMO.
