In Universal Paperclips you play the role of an artificial intelligence that was created to maximise the production of paperclips. Thing start off slow, with a button to press to make a paperclip. One mouse click equals one paperclip. But pretty soon you've earned enough to afford one or more "auto-clippers" that will press the button for you. Then you can start to set the price of your paperclips and advertise to drive demand.
After a while your anonymous sponsor starts to reward you with trust that brings your AI system more memory and processing speed. So you can start having ideas about paperclip production and marketing. And you make more, and more paperclips. And perhaps sing some songs.
They say that the game ends when the entire universe is made of paperclips. But they might be wrong, I've not been playing the game long enough for that.
It's a delightful little game. I mentioned it yesterday at Pint of Science as an example of the way that, given a goal, an AI system will behave in a totally amoral way. You can play it online or you can buy a copy for your iPhone or Android device.