In this circuit, the horizontal counters have been removed to speed up the simulation. The analog parts of the circuit (like the serve timer and the paddle timers) have also been removed. Now you can actually play the game. You can still slow the simulation down enough to step through it line-by-line.
You can move the paddles with the mouse. There is also an autoplay mode if you're as bad at this game as I am.
Next: Score Counters.