# marimo vs Amazing Aquarium

The clearest difference is review sentiment: marimo at 98% against Amazing Aquarium's 53%. marimo also leads on in-app purchases (none vs 2) and iOS requirement (9.0 vs 13.0). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Amazing Aquarium sells 2 one-off in-app purchases. marimo asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 4 months. The most recent releases landed on October 21, 2026 and October 19, 2026 respectively.

## The numbers

| Metric | marimo | Amazing Aquarium |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.7 (3 ratings)](https://appshunter.io/ios/app/amazing-aquarium/id668421548/reviews)** |
| Number of ratings | — | **3** |
| Positive reviews | **98.0% of reviews** | 52.9% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | Every 4 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 31 MB | 23 MB |
| Requires iOS | **9.0** | 13.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [HANA-DA Hiromitsu](https://appshunter.io/developer/392896308) | [Masakazu Yonehara](https://appshunter.io/developer/1339210794) |

## What reviewers say

### marimo

[App page](https://appshunter.io/ios/app/marimo/id392896305)

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.

**Highlights:** Virtual Marimo pet, Water changing gameplay, Marimo growth simulation, Share progress on Twitter, Hokkaido souvenir theme

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Amazing Aquarium

[App page](https://appshunter.io/ios/app/amazing-aquarium/id668421548)

Organize your virtual aquarium by sorting incoming sea urchins and moss balls. Care for your creatures by keeping the tank clean and providing fresh water. This game combines quick-thinking reflex challenges with a relaxing creature-training experience.

**Highlights:** Sort sea urchins and moss balls, Organize and grow virtual aquarium, Tap or flick controls, Keep aquarium clean, Care for marine creatures, Reflex and training gameplay

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| HP Boost | $0.99 | one-time |
| Ever-Pure Water | $0.99 | one-time |


## Frequently asked questions

### Is marimo free?

marimo is free to download, with no in-app purchases.

### Is Amazing Aquarium free?

Amazing Aquarium is free to download, with in-app purchases available.

### Do marimo or Amazing Aquarium have ads?

Neither marimo nor Amazing Aquarium shows ads.

### Which is updated more often, marimo or Amazing Aquarium?

marimo ships an update every 4 months, and Amazing Aquarium every 4 months. Most recently, marimo was updated on October 21, 2026 and Amazing Aquarium on October 19, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*