# Zen Koi Classic vs Aquarium Fish vs Alien

The clearest difference is price: Zen Koi Classic at Free against Aquarium Fish vs Alien's $4.99. Zen Koi Classic also leads on ratings volume (2.1K vs 16) and rating (4.7 vs 4.4). Aquarium Fish vs Alien's advantage is in-app purchases (none vs 10) and ads (none vs shown). On review sentiment, update cadence and device support there is nothing between them.

Zen Koi Classic is free to download; Aquarium Fish vs Alien costs $4.99 up front. Zen Koi Classic sells 10 one-off in-app purchases. Aquarium Fish vs Alien asks for nothing beyond the download.

Zen Koi Classic holds the better App Store score, 4.7 against 4.4. That said, the two scores are not equally well evidenced: Zen Koi Classic has 2.1K ratings behind it against 16, so its average is the more settled of the two. Written reviews point the same way: 86% of Zen Koi Classic's written reviews are positive against 82% of Aquarium Fish vs Alien's.

Both ship on a similar rhythm, roughly every 3 months. The most recent releases landed on October 29, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Zen Koi Classic | Aquarium Fish vs Alien |
| --- | --- | --- |
| Price | **Free** | $4.99 |
| Rating | **[4.7 (2.1K ratings)](https://appshunter.io/ios/app/zen-koi-classic/id896575207/reviews)** | [4.4 (16 ratings)](https://appshunter.io/ios/app/aquarium-fish-vs-alien/id6504767821/reviews) |
| Number of ratings | **2.1K** | 16 |
| Positive reviews | **85.6% of reviews** | 81.8% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 3 months | Every 3 months |
| Monetization | **Free with in-app purchases** | Paid |
| Best chart rank | — | **#123** |
| Size | 128 MB | 336 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 12+ |
| Developer | [LandShark Games Pte. Ltd.](https://appshunter.io/developer/635142101) | [Luan Nguyen](https://appshunter.io/developer/1753738963) |

## What reviewers say

### Zen Koi Classic

[App page](https://appshunter.io/ios/app/zen-koi-classic/id896575207)

Nurture and collect vibrant Koi fish in a serene underwater world. Watch them grow, evolve into majestic dragons, and discover hundreds of unique varieties. Share your collection with friends and enjoy a calming, visually stunning experience.

**Highlights:** Breed and collect hundreds of unique Koi varieties, Watch Koi evolve into majestic dragons, Soothing music and mesmerizing visuals, Intuitive single-touch controls, Share and gift Koi with friends, Limited edition rewards for collectors

**Features:** Vision Pro support

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Starter Pack | $1.99 | one-time |
| Small Handful of pearls | $1.99 | one-time |
| Handful of pearls | $4.99 | one-time |
| Hasu Pack | $4.99 | one-time |
| Bag of pearls | $9.99 | one-time |
| Tenshi Pack | $9.99 | one-time |
| Splatto Pack | $9.99 | one-time |
| Yajiri Pack | $9.99 | one-time |
| Monkī Pack | $19.99 | one-time |
| Nami Pack | $19.99 | one-time |

**What reviewers like**

- 🌊 Relaxing and calming gameplay
- 🎨 Beautiful and intricate koi designs
- 🐉 Enjoyment of breeding and evolving koi into dragons
- 🕰️ Great way to pass time and de-stress
- 🎶 Soothing and pleasant background music

**What reviewers complain about**

- 💰 Difficulty earning pearls without in-app purchases
- 🔒 Limited number of koi/egg slots without spending pearls
- 🐛 Occasional crashes and bugs after updates
- 🆕 Concerns about losing progress after updates
- 📺 Disruptive full-screen ads

**Reported bugs**

- Koi and dragon progress lost after updates
- Inconsistent koi movement and speed issues
- Ads causing frequent crashes or freezes

**Requested features**

- Ability to play as or interact with dragons
- More koi slots or alternative ways to expand pond
- Easier ways to earn pearls without watching ads
- Ability to name or customize koi and dragons
- Zoom out feature to see full pond layout


### Aquarium Fish vs Alien

[App page](https://appshunter.io/ios/app/aquarium-fish-vs-alien/id6504767821)

**Currently charting:** #123 Top Paid · Casual (US App Store)

Embark on an aquatic adventure managing a fish tank filled with guppies and other creatures. Feed your fish, collect coins, and unlock upgrades to protect your tank from alien threats. Explore different game modes, including adventure, challenge, and a virtual tank builder.

**Highlights:** Manage a fish tank, Feed and collect coins, Unlock upgrades and lasers, Adventure Mode with pets, Challenge Mode, Virtual Tank customization

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Zen Koi Classic free?

Zen Koi Classic is free to download, with in-app purchases available.

### Is Aquarium Fish vs Alien free?

Aquarium Fish vs Alien costs $4.99, with no in-app purchases.

### Which has better reviews, Zen Koi Classic or Aquarium Fish vs Alien?

Zen Koi Classic is rated higher. Zen Koi Classic averages 4.7 out of 5 from 2.1K ratings, while Aquarium Fish vs Alien averages 4.4 from 16 ratings.

### Do Zen Koi Classic or Aquarium Fish vs Alien have ads?

Zen Koi Classic shows ads; Aquarium Fish vs Alien does not.

### Which is updated more often, Zen Koi Classic or Aquarium Fish vs Alien?

Zen Koi Classic ships an update every 3 months, and Aquarium Fish vs Alien every 3 months. Most recently, Zen Koi Classic was updated on October 29, 2026 and Aquarium Fish vs Alien on October 30, 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.*