The article explains how feedback loops work in a game-related environment, and what makes them particularly useful in designing a space that also has to be educational on a fundamental level. For instance, how do I get up to that ledge to grab the rocket launcher? How can I open this door to keep progressing through this level? The gamespace and elements have to provide feedback to the user, to let them know how things work so that they can keep playing and hopefully have fun along the way.
One of our favorite quotes -- "I can put a black box on the table with a hidden button. Unbeknownst to a potential user, pressing the button enough times and the black box will spew out a thousand shiny silver coins. This is not a game. This is a bizarre gizmo." It goes on to explain how a designer would take this and turn it into a game by encouraging discovery and exploration, and by hinting that something useful (the coins) will be a result. A lot of things in this article are simple enough to make you smack your forehead, but it's really interesting to see how they work together in a game design context, and to understand the work that goes into something as simple as trying to present a path to a player.
Oh, and we want one of those black boxes with the coins inside.