Here is the full list of all 27 Eventide 3: Legacy of Legends achievements worth 1,000 gamerscore.
You finished the game in Expert mode
You stopped the ritual and defeated the King
You finished all Battle Runes Minigames without a mistake
You finished all the Minigames without skipping
You helped John acknowledge his powers
You found all the ornaments
You found all the cards from the Pantheon
You completed all Hidden Object Puzzles without using a Hint
You finished both Portal Travel Minigames without a mistake
You brought the Zmey Scepter
You found half of all cards from the Pantheon
You proved yourself and summoned Perun
You found out about the King's evil plan
You found half of all ornaments
You got out of the dungeons
You freed and healed the Cloudman
You found the Prism
You finished three Minigames in a row without skipping
You finished a Minigame in less than 1 minute
You finished a Hidden Object Puzzle in less than 30 seconds
You completed 3 HO scenes with less than 5 mistakes in each one
You got to Vyrai
You uncovered and healed Aitvar
You completed a Hidden Object Puzzle without using a Hint
You found 3 Hidden Objects in 3 seconds
You found the first card from the Pantheon
You found the first ornament