An angled disc-bullseye exploding into pieces? The actual depiction won't be as important as the graphical touches. Right now, your non-3D graphics are a little amateur.

Also, can you make the balls a little more spherical? They're the main focus of the game and the background kind of overshadows them.

Actually, why are they spheres and not discs? Discs would look better (more traditional) and add difficulty when they rotate.