Hatch & collect
Open starter, bred, event, and limited genesis eggs to grow a living collection.
BREED · EVOLVE · BATTLE
idle koi!
Hatch magical koi, breed unique bloodlines, and build teams that keep growing—even while you're away.
COMING Q3 2026 · STEAM APP ID 4855670
01 / THE GAME
EVERY KOI HAS A STORY
Grow a bloodline.
Build a legend.
Every koi begins as an egg and grows through its own genes, appearance, rarity, skills, lineage, and battle history. Breed for a chance at mutation and leap evolution, then send your best three-koi teams on idle expeditions.
WHITEPAPER · V0.1THE WORLD BENEATH THE WATER
Read the
Whitepaper.
Explore the complete design behind Idle Koi: spirit eggs, inherited bloodlines, leap evolution, 3v3 expeditions, the player market, server-authoritative assets, and the path to a living collectible economy.
15 languagesBloodline genetics3v3 idle battlesSteam economy
COLLECTIBLE KOI
Born unique.
Raised by you.
Breed bloodlines
Inherit fins, colors, expressions, hidden genes, and the chance for rare mutations.
Battle while idle
Build up to five three-koi teams for expeditions that keep fighting while you manage the rest.
THE STUDIO BEHIND THE POND
Made with care
by ANN Games.
We build collectible worlds with deep systems, distinctive characters, and plenty of room for every player to find their own rhythm.
View the official Steam pageYOUR NEXT BLOODLINE STARTS HERE