Press Left and Right arrows to control flippers. I have taken a stab at rewriting this myself. You can see my progress here: https://scratch.mit.edu/projects/213926308/
This code is taken directly from https://scratch.mit.edu/projects/681997/ I'm using this project for research on how to fix the flippers. Currently, they don't work much like a real pinball machine at all! I have 3 pinball simulations that could greatly benefit from improved flippers.