The gallery is unlocked; it seems the only thing missing is number 17.

Installation:

Download the archive with your save
Disable cloud sync (if licensed, in Steam or another launcher)
Go to the game folder
Unzip the archive contents to this folder (replace if necessary)
Launch the game
Check your save
Exit the game
Enable cloud sync (if licensed, in the same way you disabled it)
If there's a cloud sync conflict, select a local save
Done!

Author: Alicelel