I mean that the number of balls you have ends up outside of the screen when you shoot from the far right side. I don't think it matters what the ball count is. Because the ball count is always to the right of where you shoot, it sometimes ends up outside of the screen.
Its really fun! I love the particles and the camera shake. The only flaw I found was that when you shoot the ball from close to the right edge, the number of balls you have don't fit on the screen.