One of the many incarnations of the Hitchhiker's Guide to the Galaxy was a text adventure game. Similar to "Adventure" or the original "Zork," if you were into this sort of thing in the very early nineties. The text adventure genre of game works like this...in a test screen much more vacant than a word document, a room will be described to you. Then you type into the computer what you want to do. Like...
You wake up and the room is spinning. It is dark.
And then you type in...
Turn on light.
And then the computer tells you,
The light is on. You are in your bedroom.
And the interactions progress like that. I downloaded the free text version of the hitchhiker game once, and, after running into this link from digg.com to 1up.com...ran into a spiffy version of that exact same text adventure game from oh so long ago. Except it does have some graphics and a flashy interface...but the text content, far as I can tell, is just about the same.