marimo vs Medaka Aquarium Breeder
Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.
marimo
A virtual pet simulation where you nurture a Marimo, a unique aquatic plant from Hokkaido. The core gameplay involves changing its water to help it grow. You can then share your Marimo's progress with friends.
- Virtual Marimo pet
- Water changing gameplay
- Marimo growth simulation
- Share progress on Twitter
- Hokkaido souvenir theme
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Marimo-chan is an application to grow the "Marimo" on the iPhone. Inhabit Lake Akan in Hokkaido, can be observed / breeding on the iPhone the "Marimo" very popular as a souvenir of Hokkaido. Is a very simple system. Basically all you have to do change water. When Marimo grow large then Let's boast to your friends on twitter
Medaka Aquarium Breeder
Raise and breed killifish in a relaxing aquarium simulation. Manage water quality, feed your fish, and sell them to upgrade your tank. Discover new species and create a beautiful underwater world.
- Manage aquarium water quality and temperature
- Feed and grow killifish
- Sell fish to earn money
- Breed new killifish species
- Customize aquarium with equipment and layouts
- Offline play available
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Medaka Aquarium Breeder is an idle breeding game where you become a medaka breeder, manage your aquarium, and raise your own medaka fish. Adjust the water temperature and quality, feed your medaka, and watch them grow over time. Even while the app is closed, your medaka continue to grow little by little. Sell the medaka you raise to earn money, buy aquarium equipment and layout items, and create your own relaxing aquarium. A major update has expanded the breeding and collection experience. Main features added in the update: - View medaka relationships and breeding routes with the genetic map - Use Breed Points to unlock hints for undiscovered medaka and analysis for discovered medaka - Expanded breeding patterns make it possible to discover more medaka varieties - Seasonal Shop where you can obtain medaka inspired by spring, summer, autumn, and winter - Expanded encyclopedia and genetic map with more detailed information about discovered medaka - Updated Tips to make new features and breeding advice easier to understand How to play: - Manage water temperature and quality, and feed your medaka as they grow. - Feeding and cleaning take only a short time, making it easy to care for your aquarium during spare moments. - Sell raised medaka to earn money, then buy aquarium equipment and layout items. - Pair male and female medaka to produce offspring that inherit traits from their parents. - Use the genetic map and encyclopedia to search for medaka you have not discovered yet. - Check in-game Tips anytime to learn about raising medaka and using each feature. Features: - Idle growth system where medaka continue to grow while you are away - Aquarium layout customization with equipment, sand, aquatic plants, stones, and more - Collection gameplay where breeding can lead to new medaka varieties - Encyclopedia to review discovered medaka - Genetic map to check parent-child relationships and breeding clues - Seasonal Shop where different medaka appear depending on the season - A calm aquarium atmosphere with water sounds and music The medaka available in the shop are only part of what you can discover. Some medaka can only be created through breeding, and others are connected to the seasons. Think about parent combinations, unlock hints with Breed Points, and work toward completing your encyclopedia. Recommended for players who: - Enjoy raising games that can be played little by little - Like aquariums and relaxing water-themed experiences - Enjoy caring for virtual pets - Like discovering new varieties through breeding or pairing systems - Want to steadily complete an encyclopedia or collection - Want a calm game to enjoy during breaks or quiet moments Raise medaka, breed new varieties, expand your encyclopedia, and create your own aquarium.
Screenshots
Verdict
The clearest difference is ads: marimo at none against Medaka Aquarium Breeder's shown. marimo also leads on monetization model (free vs ad-supported) and iOS requirement (9.0 vs 13.3). Medaka Aquarium Breeder's advantage is update cadence (every 11 days vs every 4 months). On price, review sentiment, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
marimo ships an update every 4 months, Medaka Aquarium Breeder every 11 days. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.
| Parameter | marimo | Medaka Aquarium Breeder |
|---|---|---|
| Price | Free | Free |
| Rating | — | 4.3 (3 ratings) — better |
| Positive reviews | 98.0% of reviews | 100.0% of reviews — better |
| Number of ratings | — | 3 — better |
| Update frequency | Every 4 months | Every 11 days — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free — better | Ad-supported |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 9.0 — better | 13.3 |
| Further details — not scored | ||
| Size | 31 MB | 244 MB |
| Age rating | 4+ | 4+ |
| Developer | HANA-DA Hiromitsu | Yuki Naruse |
Customer experience
marimo
Medaka Aquarium Breeder
In-app purchases
marimo
No in-app purchases
Medaka Aquarium Breeder
No in-app purchases
Questions
Is marimo free?
Is Medaka Aquarium Breeder free?
Do marimo or Medaka Aquarium Breeder have ads?
Which is updated more often, marimo or Medaka Aquarium Breeder?
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