I don’t know if this is helpful, but I have made a list of all events 2015 - Present (I began in January 2015)
Japanese Island
Carnival Adventure
Atlantis Island
Easter Island
Titan Island
UFO Island
Throne Island
Celestial Island
Farm Island
Woods Island
Dungeon Island
Hollywood Island
Halloween Island
Five Seasons Island
Labyrinth Island
Snow Adventure Island
Sun and Moon Island
Oni Island
Idol Island
3rd Birthday Island
Pirate Island
Epic Journey
Panda Island (iOS only)
Heroic Race High Fenrir (pc and android only)
Inner Earth Island
Heroic Race High Fenrir (iOS only
Celestial Island (pc and android only)
Jungle Island
Atlantis Island
Heroic Race High Nucleus
Wacky Lab Island
Heroic Race High Tension
Summer Island
DC Games
Holiday Island
Heroic Race High Guardian
Galactic Island
Frankenstein Island
Heroic Race High Priest
Amusement Park Island
Magic Forest Island
Heroic Race High Tidal
Vampire Island
Blizzard Island
Heroic Race High Comet
Winter Farm Island
Glacial Tower
Jungle Island
Heroic Race High Realm
Fairytale Island
Valentines Island
Heroic Race High Entity
Apocalypse Island
Cursed Rose Island
Heroic Race High Supremacy
DC 2056
Throne Island
Heroic Race High Spirits
Galactic Island
Happy Inferno Island
Pirate Island
Heroic Race High Amuka/Fighter
Frankenstein Island
Video Game Island
Summer Island
Heroic Race High Star
Dungeon Island
Ragnarok Island
Wacky Lab Island
Heroic Race High Queen
Colossus Island
Holiday Island
Heroic Race High Purity
Jungle Island
Comic Book Island
Blizzard Island
Heroic Race High Octane
Vampire Island
Apocalypse Island
Shadow Island
Heroic Race High Tech
Oni Island
Dragon Justice Island
The Shire Island
Heroic Race High Snow
Snow Island
Illusion Island
Burglar Tower Island
Farm Island
Heroic Race High Portal
Blizzard Island
Fire and Ice Island
Snow Island
Heroic Race High Celestial
Happy Inferno Island
Turbo Island
Oni Island
Heroic Race High Superstition
Jungle Island
The Shire Island
Watchtower Island
Magic Castle Island
Neo-Tokyo Island
Heroic Race High Resolution
Conqueror’s Island
Ragnarok Island
Dragon Wars Island
Beach Island
Heroic Race High Score
Pyramid Island
Crazy Lab Island
Alliance Race High Feral
Ruined Tower Island
Fae Land Island
Fae Queen Castle
Heroic Race Yggdrasil + DC 2056
Moon Elevator Island
Wasteland Island
Heroic Race High Commander + DC Games
Dark Adventure Island
Fun Fair Island
Chocolate Tower Island
Fruit Puzzle Island + Turbo Island
Championship Island
Heroic Race High Reverie + Illusion Island
Thieving Tower Island
Hallo-Muertos Island
Comic Book Island
Alliance Race High Zephyr
Catacombs Island
Pallet Tower Island
Far West Puzzle Island + Arcade Island
Divination Island
Seasons Island
Weather Machine Island
Heroic Race High Winter
