Benji Bright (@benji_bright (http://www.twitter.com/benji_bright)) sent me his text adventure game made in Twine on Twitter, and I think it'd be a good example to show what Twine can do!
Play it here : http://t.co/U6HLrx7B (http://t.co/U6HLrx7B)
If you know a little bit of HTML, you can add image to each scene too, so you can make it like a choose-you-own-adventure book with illustration. :)