The Grim Fandango Puzzle Document is the game’s initial pitch document written by Tim Schafer. The manual and original music score are also available.
Released
The Doom Bible
The Doom Bible is the original design document for Doom, written by Tom Hall in 1992. Not much from this document was used in the original game, but it’s an interesting read.
Classic LucasArts Game Design Documents
Aric Wilmunder has released many of the original LucasArts Game Design Documents on his personal website. He is still busy adding new documents, but the following files can be seen on his website at this moment:
- Monkey Island
- Day of the Tentacle
- Maniac Mansion
- Star Wars Rebel Assault
- Shadows of the Empire
- Defenders of Dynamo City
- The Telecommuter
- Labyrinth
- Indiana Jones and the Last Crusade
- Sam & Max
- The Dig
- Curse of Monkey Island.
EDIT: Aric Wilmunder’s website seems to be offline, luckily the Internet Archive made a snapshot of the page with the game design documents
WipEout Game Design Document
For the 20-year anniversary of WipEout (PS1) the game designer Nick Burcombe, who worked at UK developer Psygnosis, has released the official Game Design Document.
Monaco Game Design Document
The developer for Monaco has released the original game design document on Facebook.
Bioshock Pitch document by Irrational Games
Diablo 1 pitch
David Brevik was one of the original members of Blizzard North. He has released the pitch document for the original Diablo on his website.