Several backers have been reporting that their Myst 25th Anniversary Linking Books have started arriving.
Rium has posted a review upon his blog with plenty of pictures.
“The Myst 25th Anniversary Kickstarter rewards are finally getting sent out! Since I got lucky & somehow managed to be one of the first in the world to gain access to one, I thought I’d post some photos & a bit of a review of them. Fair warning, this post is gonna be a bit long & a bit image-heavy, but that’s probably what you’re looking for anyway!”
You can read his review here if you don’t mind being spoiled: https://www.riumplus.com/myst-25th-anniversary-kickstarter-rewards-review/