In addition to being mildly educational, the Time Machine series of books solved a problem that I had with the Choose Your Own Adventure series: arbitrary game over states you would achieve due to a choice, prompting you to start the book over. No one ever did that. You kept a finger in the book at the page where you made your last risky choice, to go back to if you got "The End." This finger is the prototype for the (forgive the pun) "manual save system" in video games today. "Save scumming" simply involved multiple fingers! The most advanced readers of non-linear fiction min-maxed the experience to read the book in the most non-linear fashion possible!

Repitition Leads to Mastery

By contrast, the Time Machine series of game books featured fewer choices and branches, but with more story passages and developments devoted to each branch. As a consequence and a benefit, zero pages were devoted to game over "The End" states. When a reader was presented with a choice in a Time Machine book, it was a choice that ideally should have informed by something the reader learned about the period in a previous passage, and not something arbitrary and unpredictable. In essence, the questions were little quizes about the period you had been experiencing and its key figures (i.e. who to trust? etc.). If you made a bad choice in the Time Machine series, you would be thrown back to an earlier passage in your stream of choices, very much like how modern video games determine an autosave point from which you can continue after failing.