There are a couple of errors in the code for this episode. One is that you have put the code for checking bounce of ball against paddle above the sound player playing the ping, so it won’t play. Also you have the code for checking bounce of ball against bricks above the sound player and you also don’t set the bounced flag to true.
This has been an excellent course. I use Unity a lot and the understanding this course has given me of the lower level things that go on when rendering with the GPU is immensely valuable.
I’m very glad you found it useful. I agree that even if you never use Metal directly, it’s easier to understand how to organize things at a higher level, and hopefully be more creative with Unity’s shaders.