The technical design document: later videos (link below) cover environment and level design and characters.
i3D Tutorials has posted an interesting series of timelapse videos showing the creation of a Unity game.
The series of six videos, which total over 30 minutes of footage, show the development of a first-person shooter, from the creation of a technical design document (above) to the first working build.
The end result is more of a tech demo than a complete game, since it features only a small environment and no enemy AI, but it does include a complete shooting system and some quite sophisticated physics, including partially destructible scenery.
Asset creation is done in 3ds Max and Softimage, with later videos in the series covering environment lighting using Unity’s Beast lightmapping engine.
There is no narration, so how much you can pick out depends on how familiar you are with the tools being used, and the character animation video is really just a demo of the rig; but it’s still a fascinating overview of indie development workflow.