From the inside: «Mind games anticipate the play-learning systems of the future, opening that future to you now. Mind games are education, ecstasy, entertainment, self-exploration, powerful instruments of growth. Those who play these games should become more imaginative, more creative, more fully able to gain access to their capacities and to use their capacities productively.»
The book has some nice recommendations for it including the one on the front cover given by John Lennon.