Works indeed, nice! Didn't really play it thoroughly yet, only checked if it works, but some early remarks:
Looks good, nice concept! It does feel a bit sluggish, especially waiting until the ball came to a full stop.
I got my ball behind the horizontally moving walls, making it impossible to escape. It takes too long for the ball to come to a full stop, so the wall hits the ball again before I'm able to hit it, I don't think it can recover from being trapped.
What could help with both points is to be able to hit the ball while it's still moving.