I've played through this game before, but it's been a few years. I played the first couple of levels without any problems, but had trouble on the third stage (the opera house). I think that it's a case of remembering enough to know what to do, but not enough details to make it happen. In any case, I am a big fan of this game, particularly because there is still really no other game like it. It's very unique being able to blend in with the crowd and killing people without others noticing or even believing that it is murder.