Clark Aldrich once said that about educational games that:
    "Game elements are the spoonful of sugar that helps the medicine go down." (“Learning by Doing”, p. 85)

This is the attitude that learning is boring, and that we need to add the game elements to an educational game in order to make it bearable. I fundamentally disagree with this approach to educational game design. One of the central themes of Raph Koster's A Theory of Fun for Game Design, is that fun comes from learning new skills. Games get boring once we master the skills needed to play them, and they get frustrating when we aren't able to gain enough competency. That's why it's important to make sure your games difficulty curve is optimized to constantly be just challenging enough.