For many of us non-digital-natives over 30, our first contact with interactive technology came about through playing video games. Long before personal computers and mobile phones became part of our daily lives, we were already hooked on these games. In places as diverse as Chile, Greece, and Finland, at the arcade or at home (for example, with the Atari 2600), there was something powerful about these games that had us captivated from the very first moment we played Donkey Kong, Centipede, or Pole Position. But what made them so interesting and intriguing? What made us go back regularly (even daily) to the arcade? Over the years, games scholars have been studying some of these issues [1]. But could some of the power behind video games be channeled to motivate people and help them achieve their goals? Could playful designs inspired by what makes games fun and entertaining help create better user experiences? (acm.org)