Haha, this is great fun. Scratching my own itch and making him turnaround when you scroll up:

  /* Add style */
  #scrollBuddy.walkUp {
    transform: rotate(-90deg) scaleX(-1);
  }

  /* Amend script */
  var lastTop = 0;
  function updateBuddyVerticalPosition(scrollPosition) {
    // All as before but add the below before requestAnimationFrame
    if (lastTop <= newTop && buddy.classList.contains('walkUp')) {
      buddy.classList.remove('walkUp')
    } else if (lastTop > newTop) {
      buddy.classList.add('walkUp')
    }
    lastTop = newTop;
  }