Step One: Click the green flag. Step Two: Place your cat on the keyboard. Step Three: Try to prevent cat from powering off computer, clawing screen, and sending your friends messages like usyf'q;3vtH6IEya.
I got the idea from my cat Milo, a little orange kitten who loves climbing on the computer while I'm working on Inform. His favorite word is "nv[r77j7no0ooop2čtfec1cqb". So far the only keys that work are a, b, c, d, e, f, g, and h.