OK, so the software/simulator version is done. I'll probably get a C or D for this version.

https://wokwi.com/arduino/projects/290809734244598280

Done: The ball bounces, the bats move, it stop when it hits the wall either side

Underachievment: buttons debounced by screen framerate, ie player can only move his bat once for every ball move, and button must be depressed at the framechange (a short press will be missed)

I need two "timers", one for debounce and for framerate. Plenty of ways to do this and still avoid using a real timer. I could use one to show I understand interrupts. 

Sidenote: Interrupts are evil little things. They destroy the predictability of a program. A friend who worked on machines when coremagnetic memory was "hot", said: "The computer lost it's innoncence when interrupts were included". So true, so true.

Its 30th of March, so ... likeyhood of me improving it is low. I'm going back in the mancave and see if I can complete the hardware version