Nanoquest - a game to learn about nano technology
I don't know if Nanoquest would fall into Schaffer's definition of an epistemic game, but it certainly taught me a heck of a lot more about what nanotechnology is and how the elements that make it up play off each other.
That said, I'm a teacher and looked at the teacher notes after having some fun in this first-person seek-'em-out-type game, chasing after nano parts for my nanocar before driving it across some particularly static and sticky gold nano plates to the wormhole. But I thought that, as an introduction to the world's fastest growing technology sector, it wasn't bad at all and gave the fun element to science where, to be honest, it's difficult for the school to provide a realistic firsthand experience.
It's available as a download or, like me, you can play the web-based Flash version. (Thanks Dan at Flux).