An educational game about shelving books, and more thoughtful than that description suggests. You walk with A and D, press space to interact with whatever the pop-up highlights, and sort each book into its Dewey Decimal range from 000 to 900 — a real classification, taught by use rather than explained. The public setting has more to it than the shelves: there are things to find past them, and a poster worth actually reading.
What went wrong?