Book and game
The book and game idea is simply to require that the player must have read a book because otherwise the related game remains unplayable.
A book could be a novel with educational content. The educational content would be equally required to play the game so the player would be motivated to train reading skills by reading the novel and to learn the educational content.
Unlike similar educational games, such as, for instance, Mathica, parts of a novel would be required as a precondition to be able to play the game. The OLPC would, of course, have the advantage of being the book at the same time, so the player could switch conveniently from playing the game to reading the novel and the novel would then contain educational content and riddles that required understanding for earlier information. The game could then rely on both.
One could give the novel and the game a timeline and the player would be in the future (lacking relevant information) if he had not read the novel. This way the motivation to want to know what is in the novel becomes the pupil's own motivation, not a homework assignment.