12 o’clocks was released in 1996, on CD-rom, by John Maeda. It was part of his Reactive Books series (1994-1999)
each book explored the use of a different input: microphone, mouse, time, keyboard, and video. At a time when interactive media was trying to be more and more, the simplicity and focus of these pieces set them apart. Their visual simplicity allowed you to really pay attention to the nuances of the interaction. And their code-based design made endlessly playable.
— http://www.inventinginteractive.com/2010/07/08/reactive-books/
There is now a collaborative port of 12 o’clocks on p5.js, here: https://codingtrain.github.io/12oclocks/, so you can play it in any modern browser (instead of having to boot up an old Mac emulator)