hide another go until the end
new global
var g_another_el;
setup()
function setup()
  ...
  g_another_el=document.getElementById('another');
  g_another_el.style.visibility='hidden';
}
computer()
function computer() {
  ...
    el.textContent=g_player_count;
    g_another_el.style.visibility='visible';
  }
}
square_clicked(el)
function square_clicked(el) {
  ...
      el.textContent=g_computer_count;
      g_another_el.style.visibility='visible';
    } else {
     setTimeout(computer,2000);
    }
  }
}