this sent me down a rabbit hole of circuit based games, thanks for sharing. I found this article about pong that goes into the details and logic behind each of the circuits: http://www.pong-story.com/LAWN_TENNIS.pdf
I found it via https://news.ycombinator.com/item?id=17200163 "... an insanely clever masterpiece of digital design. ... It’s mindbendingly brilliant."