Very interesting: "Tarn sees his work in stridently ethical terms. He calls games like Angry Birds or Bejeweled, which ensnare players in addictive loops of frustration and gratification under the pretense that skill is required to win, 'abusive' -- a common diagnosis among those who get hooked on the games, but a surprising one from a game designer, ostensibly charged with doing the hooking. 'Many popular games tap into something in a person that is compulsive, like hoarding,' he said, 'the need to make progress with points or collect things. You sit there saying yeah-yeah-yeah and then you wake up and say, What the hell was I doing? You can call that kind of game fun, but only if you call compulsive gambling fun.' He added: 'I used to value the ability to turn the user into your slave. I don’t anymore.'"