The joker is hard to play for me. He doesn't have the X-ray vision at all times like batman, he has to stand still in an upright position (so no hiding) to use it. He also can't swing around and use the gargoyles like Batman can. Using him to take out the guards is really hard. You basically have to be really good at the combat, or sneaking around without using any of Batman's gadgets with a lot of patience.