Comparison

The Marimo vs Medaka Breeder

Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.

Head to head
About

The Marimo

Care for a virtual green ball creature that grows over time. Keep its environment clean and provide light to ensure its survival. Customize its appearance and interact with it through various gestures.

Highlights
  • Virtual pet care
  • Growth simulation
  • Environment maintenance
  • Customization options
  • Interactive controls
  • Social sharing
Features
Read full description

Thank you 1,130,000 download!! [About Marimo] Marimo means a plant like a green ball which grow in Hokkaido, Japan. You can raise a Marimo. A marimo will grow up little by little every day. When water become dirty, you need to refresh water. If you don't take care of a Marimo long time, Marimo will wither. [Other Features] - You can rename Marimo, and change background. - Drag to move Marimo. - Double tap to pick tap Marimo. - Rotate marimo with two finger. - Marimo moves by the direction of the device. - You can upload image of Marimo on Twitter/Facebook. - Photosynthesis occurs in a bright place.

About

Medaka Breeder

Experience realistic fish keeping by feeding and cleaning your virtual fish. Watch them grow, breed, and inherit traits from their parents. Customize aquariums and collect various fish species.

Highlights
  • Realistic killifish keeping simulation
  • Breed fish and inherit traits
  • Customize aquariums with decorations
  • Collect over 46 types of killifish
  • Missions and rewards system
  • Observation and shooting modes
Features
Read full description

[Game Features] You can experience realistic killifish keeping in your phone. Taking care of your killifish is very easy: just feed them once every three days and clean the tank. The killifish will eventually grow over time and breed with other adult killifish (2cm or larger). The killifish born from the breeding will inherit the characteristics of their parents. A maximum of 50 killifish can be kept. Up to 10 killifish can be kept in one tank, Up to 5 aquariums can be set up. Functions ■Mode switching Default: Information on the killifish and aquarium is displayed, allowing the user to check the status of their care. Observation: Hides the display of information, allowing you to closely observe the aquarium and killifish.    You can also tap on the water surface or the aquarium area to see if there is any reaction! Shooting: This function is useful when you want to hide the information and buttons and take pictures of only the killifish and the aquarium. ■Name your killifish You can name each killifish. You can name each killifish so that even if you have a lot of killifish, you will never lose track of them. Layout of the aquarium You can keep your killifish in your favorite decorated aquarium. There are a total of five types of layouts. Layout types: tank appearance, bottom sand, stones, plants, and ornaments. ■ Shop You can purchase killifish, aquariums and ornaments. There are 46 types of killifish sold in the store! ■Missions You can receive rewards by accomplishing various missions. You can purchase more items such as killifish and aquarium tanks by challenging many missions. ■Revival Chance If you are too busy to take care of your killifish and let them die, don't worry! You can bring them back to life with the Resurrection Chance! Premium Pack (paid feature) Clear ads from auto-display. - Eliminate banner ads - Eliminate interstitial ads Relief mode is released (can be switched). - killifish won't die. Useful functions added - Collective feeding - Collective cleaning All items can be purchased Daily mission rewards tripled 50,000 G present

Screenshots

The Marimo3 screens
Medaka Breeder4 screens

Verdict

The call

The clearest difference is ads: Medaka Breeder at none against The Marimo's shown. Medaka Breeder also leads on update cadence (every 5 days vs every 3 months) and rating (4.6 vs 4.4). The Marimo's advantage is monetization model (ad-supported vs free with in-app purchases) and review sentiment (79% vs 67%). On price, ratings volume, 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Medaka Breeder holds the better App Store score, 4.6 against 4.4. Both are backed by a comparable volume of ratings — 16 and 17 respectively. Written reviews complicate that: 79% of The Marimo's written reviews are positive against 67% of Medaka Breeder's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

The Marimo ships an update every 3 months, Medaka Breeder every 5 days. The most recent releases landed on November 6, 2026 and November 3, 2026 respectively.

Scorecard6 real differences · 4 level
The Marimo versus Medaka Breeder: the parameters behind the verdict, then further details
ParameterThe MarimoMedaka Breeder
PriceFreeFree
Rating4.4 (16 ratings)4.6 (17 ratings) — better
Positive reviews78.9% of reviews — better66.7% of reviews
Number of ratings1617 — better
Update frequencyEvery 3 monthsEvery 5 days — better
AdsYesNo — better
In-app purchasesNoNo
MonetizationAd-supported — betterFree with in-app purchases
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS15.612.0 — better
Further details — not scored
Size18 MB91 MB
Age rating4+4+
DeveloperKosuke OgawaTaiho Yanase

Customer experience

The Marimo

All ratings16 ratings
Positive87.5%
Neutral6.3%
Negative6.3%
Written reviews95 reviews
Positive78.9%
Neutral11.6%
Negative9.5%

Medaka Breeder

All ratings11 ratings
Positive90.9%
Neutral9.1%
Negative0.0%
Written reviews3 reviews
Positive66.7%
Neutral33.3%
Negative0.0%

In-app purchases

None

The Marimo

No in-app purchases

None

Medaka Breeder

No in-app purchases

Questions

Is The Marimo free?
The Marimo is free to download, with no in-app purchases.
Is Medaka Breeder free?
Medaka Breeder is free to download, with no in-app purchases.
Which has better reviews, The Marimo or Medaka Breeder?
Medaka Breeder is rated higher. The Marimo averages 4.4 out of 5 from 16 ratings, while Medaka Breeder averages 4.6 from 17 ratings.
Do The Marimo or Medaka Breeder have ads?
The Marimo shows ads; Medaka Breeder does not.
Which is updated more often, The Marimo or Medaka Breeder?
The Marimo ships an update every 3 months, and Medaka Breeder every 5 days. Most recently, The Marimo was updated on November 6, 2026 and Medaka Breeder on November 3, 2026.

Other comparisons