Here is the full list of all 25 Earthlock: Festival of Magic achievements worth 1,000 gamerscore.
Level up all characters to level 20
Defeat one of every enemy
Get to the memory chamber
Return all barnacles to Plumpet Island
Rescue Benjo
Lady Lumia crafts the Lys Aegis Talent
Fill up the garden with plants
Open 50 chests
Find Pat in the warehouse
Olia rejoins the party
Help 50 ghosts to rest at peace
Defeat the Mushriga
Rescue Taika from the Bandit
Harvest 1000 fruits
Help Ive from the crashed plane
Arrived at Plumpet Island
Gnart joined the Party
Defeated the Temple Guardian
Completed the game
Levelled every type of plant to level 3
Crafted one of every Perk Talent
Levelled up all Bonds to level 5
Equipped a Talent in every available slot
Gained Gold Rank on all Tournaments
Defeated the Hollow Knight