Koi Harmony

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Rules and Gameplay

The captivating Koi Harmony slot by Rarestone Gaming offers a simple yet elegant gameplay experience. It features a unique assembly mechanic where players aim to align koi fish parts on the game’s single payline. Starting bets are as low as $0.10, appealing to casual players, while high rollers can stake up to $500 per spin. This game stands out for its low-medium volatility and a generous RTP of 96.47%, making it a great choice for both new and experienced players seeking a tranquil gaming atmosphere with straightforward rules.

Bonus Features

Koi Harmony enriches the slot experience with its engaging bonus features. Notably:

  • Respin Feature: Triggered by landing a combination that includes at least one rainbow fish segment, granting players a respin where all symbols adopt a random but uniform color, enhancing the chance to align them and win.

This innovative feature adds an extra layer of excitement, encouraging players to keep spinning for those elusive winning combinations.


The serene world of Koi Harmony is brought to life through its beautifully designed symbols, all centered around the theme of koi fish. Key symbols include:

  • Mixed fish – Most common, yields 8x the bet
  • Purple, Green, Red, Yellow fish – Offer higher payouts, ranging from 20x to 100x the bet
  • Rainbow fish – The slot’s jackpot symbol, rewarding lucky players with 888x their bet

Each symbol plays a critical role in the game’s mechanics, with the ultimate goal of assembling a complete koi fish on the payline to secure a payout.


Payouts in Koi Harmony are designed to reward players handsomely for their efforts. Notable payouts include:

Symbol Payout (x bet)
Mixed Fish 8
Purple Fish 20
Green Fish 40
Red Fish 60
Yellow Fish 100
Rainbow Fish 888

These payouts highlight the game’s potential for high rewards, especially for players lucky enough to align the rare rainbow fish.


Koi Harmony stands out with its singular payline, which is central to its gameplay. This innovative approach focuses on assembling different parts of koi fish across this single line. While it simplifies the game, it also introduces a unique challenge and excitement, distinguishing Koi Harmony from traditional multi-payline slots.

Pros & Cons

Pros Cons
Visually appealing design Basic audio effects
High RTP of 96.47% Limited bonus features
Simple yet engaging gameplay May not appeal to players seeking complex slots

Minimum and Maximum Bet

The betting range in Koi Harmony caters to a wide variety of players, with a minimum bet requirement of $0.10, making it accessible for those looking to enjoy the game without a high stake. On the other end, high rollers have the opportunity to escalate their game by placing up to $500 per spin. This flexible betting range ensures that Koi Harmony is suitable for players of all budgets and play styles.

Game Jackpot

Koi Harmony offers a compelling jackpot of 888 times the player’s bet, standing out as a significant potential win for those lucky enough to align the elusive rainbow fish symbol. This jackpot is complemented by the game’s RTP (Return to Player) of 96.47% and its low-medium variance, indicating that while wins may not be exceedingly frequent, the game pays out a reasonable amount of the time, striking a balance between risk and reward that many players will find attractive.

About Provider

Rarestone Gaming, the developer behind Koi Harmony, has established itself as a reputable provider in the online slot game market. They are known for creating visually appealing games that are both innovative and engaging. Rarestone Gaming focuses on quality over quantity, ensuring that each release is meticulously crafted to provide an enjoyable and fulfilling gaming experience. Their dedication to excellence and unique game features have pleased many in the gaming community, despite the studio not chasing the superstar status that others might.

How To Play

  1. Start by setting your bet amount, choosing anywhere between $0.10 and $500 to suit your budget and risk preference.
  2. Once your bet is set, initiate a spin to start the game. The objective is to align koi fish parts across the single payline.
  3. Pay attention to the symbols as they land. The game’s main goal is to assemble a complete koi fish, with different colors offering various payouts.
  4. If you land a combination that includes at least one rainbow fish segment, you’ll trigger the Respin feature, offering a chance for higher wins.
  5. Continue spinning as you wish. Remember, the game’s jackpot is worth 888x your bet, achieved by assembling a rainbow fish.


Koi Harmony by Rarestone Gaming is a testament to the beauty of simplicity in slot design. With its tranquil theme, straightforward gameplay, and the potential for significant payouts, it offers a refreshing alternative to more complex slots. The game’s high RTP and low-medium variance make it an appealing choice for players seeking a balanced gaming experience. While it may have its drawbacks, such as basic sound effects and limited bonus features, Koi Harmony’s charm lies in its visual appeal and the unique challenge of assembling koi fish on its single payline. For those in the market for a slot game that’s easy to understand yet rewarding, Koi Harmony is certainly worth a spin.