Quote: "If you improve it too much then the ball wont run as smooth."
Well, possibly, but I doubt AppGameKit will slow much just by improving the look of the graphics, only if you add more in. It reminds me of a pinball sim I started in AppGameKit, it's graphically very similar(bright colours and not much detail). I never intended those to be the actual release graphics though. It depends on what you want I suppose, at the minute it looks very retro.
Still, a pinball game can live or die on it's graphics, and you really want to spend as much if not more time on those, than the actual program. Pinball Dreams and Fantasies would probably not have been as popular if the graphics weren't as good as they were.
Perhaps a video as well to see how it plays?
I would also consider posting your pics using the image button when you post.
I sometimes don't even look if the picture isn't in front of me. I'm sure I'm not the only one, and I am sure you want as many peeps to see it as possible.