Good games are built to engage us and keep us playing. How do they do that? Danc over at Lost Garden has devoted considerable thought to this question and has written a compelling and very readable essay that attempts an answer.
"At the heart of every game are these mysterious whirring clicking mechanisms that deliver to the player pleasure and thrills."
He goes on to discuss feedback loops, humans as "infovores" and burnout vs. grinding. He even includes a cool color diagram! The essay originally appeared last year, but it's well worth your time and full of useful insights. If you've read Ralph Koster's A Theory of Fun for Game Design, this essay is a useful extension of that.
Full article here.