Very good. Original too!
This is a good twist to the regular Pong game. The only thing that I didn't like too much was the disco effect. I, for one, have no actual problem with it, but you should put a warning about flashing lights (for all those who might get seizure from it). Or add it in the Author's Comments section.
I really liked the "ghost balls" and big "spinning square" challenge that came up. I was not expecting it! Very nice.
I approve. If you make more, they will come. Or at least I will =p I like your style, it's really interesting to see these kinds of things.
Stay awesome, and don't stop truckin' !!