No one does guide books quite like the Japanese. Years before such tomes became fashionable as pre-order bonuses here in the west, gamers in Japan were enjoying intricately detailed publications which covered elements such as level designs, walkthroughs and secrets.
However, some of these guides went the extra mile and contained gorgeous exclusive artwork and other visual elements - such as this vintage Super Mario 64 guide, unearthed by Twitter user Clay-zulah. As you can see, entire stages have been rendered in clay, a process which must have taken quite some time.
You can never have enough clay.