Double Fine's Tim Schafer's posted the original design document from Grim Fandango.
The LucasArts point and click adventure is revered by many as a classic. It was, Schafer notes, possibly a little too hard, however.
"People said the puzzles in Grim were super hard, and I’ve always maintained that this was due to a deep character flaw or mental illness on the part of the player," he said.
"But now, reading this again, I’ve realized that holy smokes: some of them puzzles were nuts. Obscure. Mean, even. I blame Peter Chan, because he will never read this post to know that I blamed him."
Get the doc through the link.