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