When working on my piece, I decided to experiment with an idea that when the user hits the balls they disappear. I edited my existing code so that instead of ascending when they hit a black pixel, they now disappear. If I was to develop this idea, I would create it so they pop like a bubble, rather than just immediately disappearing. Here is a video clip showing the experiment:
I think this works well and with further improvements could look better. However, after talking to my audience, and showing them my progress so far they preferred my initial idea of being able to obstruct falling objects. I will continue to work on my idea, developing the programming for it.