Here is the full list of all 28 The Eyes of Ara achievements.
Loot the treasure horde
Find Astra's missing paintings
Read each copy of Christopher's favourite book
Spend 5 minutes stargazing in the Planetarium
Locate Baron Contington's Hidden Trophy Room
Complete Chapter 2
Locate Lady Catherine's Secret Room
Complete Chapter 1
Find your first Blue Orb
Complete the Tutorial
Complete Chapter 3
Complete the Epilogue
Unlock the door to the Altar of Night
Collect Christopher's scattered coin collection
Reunite Alexander's lost action figures
Assemble Clementine's scattered photo album
Locate the Backer's Gallery Secret Room
Turn off all of the Radios
Read each of Christopher's journals, Clementine's scattered journal pages, and Astra's notes
Read each copy of "The Edge of Infinity" and all "Wonders of Space" posters
Read each of the Backer's Books
Find Mike's lost coin collection
Discover an odd star formation using the telescope
Locate the Mountain Bräu Brewery
Extinguish all of the blue Jack-'o-Lanterns during the Haunted Halloween seasonal event.
Find a way into the Pumpkin Lord's Tomb during the Haunted Halloween seasonal event.
Find all of the children's letters to Santa during the Merry Mysteries seasonal event
Open the gift during the Merry Mysteries seasonal event