The game presents you with a blocky point-and-click adventure interface; as you click around and explore, you will find your choices leading you down increasingly eccentric avenues — until suddenly you hit the edge of the world. Say you click on a path leading to a fountain, but there is no target page to the click. You are then dumped into a simple image editor, where you can paint the scene yourself and designate however many links you like, to however many other pages.
Rather like a wiki, you can also edit existing pages — though in doing so it pays to be polite and cautious, as that’s someone else’s work you’re tweaking. Come to think of it, I guess Playpen would be best described as the Wikipedia of adventure games. Which is to say, imagine Wikipedia as a videogame.
As you’d expect, Farbs has set up a whole community around the project, with discussion boards, edit histories, and user preferences. You’re perfectly free to camp out your own corner of the world, invite your friends, and flesh it out to your heart’s content.
And there you have it. Go on and get creative. Be civil, and don’t get pulled into stupid politics. Pip pip!