The good news is that every first print of the retail game will include two limited sticker sheets, a reversible alternate cover, an Isaac face sticker, and a full-colour 20-page instruction booklet.
Remember when games came with instruction booklets? Oh how fun those were to whet one's appetite on the ride home from the store. This one even hearkens back to the days of yore with its Zelda-referencing cover. Fitting as pretty much everyone who buys is a Switch is going to gorge on Zelda for the first few weeks after the console's launch anyway.
These instruction manuals are only going to be included with first prints though. After that there won't be any way of acquiring these collector's items, save eBay and the like.