Here is the full list of all 34 EARTHLOCK achievements.
Defeated the Temple Guardian
Gnart joined the party
Arrived at Plumpet Island
Helped Ive after she crashed the plane
Rescued Taika from the goblin
Olia rejoined the party
Assembled PAT
Liberated the Great Wave
Received the Lys Aegis Talent from Lady Lumia
Arrived at the Memory Chamber
Completed the game
Defeated one of every enemy
Opened 50 chests
Harvested 10 000 fruits
Levelled every type of plant to level 3
Grew a plant in every garden slot
Crafted one of every Perk Talent
Levelled all characters to level 20
Levelled up all Bonds to level 5
Equipped a Talent in every available slot
Released all the barnacles to play on Plumpet Beach
Released 50 tormented Ghosts
Gained Gold Rank in all Tournaments
Defeated the Mushriga
Defeated the Hollow Knight
Planted one of every critter plant
Released all the Golden Bibis
Scavenged all scrap piles
Dug up all treasure zones
Crafted one of every weapon
Filled the library with mementos
Got all the paintings for Plumpet Library
Cured Benjo and rescued Bran
Unlocked all prison cells in Karba Prison