I've made a game with Twine. It's called Re-Entry, and you can play it for free in your browser by downloading it from the Interactive Fiction Database.
The rest of the post is about what I was trying to achieve with the game, which means spoilers, so go and play it now! It takes about half an hour, you can't lose, and the ending changes depending how you behave. If you like it, please do rate it and leave a review on its IFDB page, then head back here for some behind-the-scenes goodness.