Found the green key

Found Secret Treasure #1

Found the red key

Engaged a strange device

Rang the Western Bell

Understood the margin of page 17

Perfectly executed a special technique

Found a sword

Found a stick

Defeat the Calamity in NG+

Attain the rank of Grand Maester in the New League of Wizards

Return after experiencing death.

Own one of every shop item in the game