Nes Smash Sprites

[nicktheslayer]

As I already said, they look ugly. I would also complain about the really ugly colors, but since you said that you would change them, I'll stick to the ugly shading, ugly shape, ugly etc.
Compared with the other sprites, the ball looks like a piece of paper cutout.

Whats wrong with the shape?

Its a circle, there isnt much to work with.

And its not really shading, its just like the color growing room within, changing the color with a smoother animation, rather than just blinking.