Comparison

Zen Koi Classic vs Aquarium Fish vs Alien

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

Head to head
About

Zen Koi Classic

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
Read full description

Looking for a relaxing game? Dive into Tranquility: Unwind and Ascend with Zen Koi Classic (Free-to-Play) Embark on a captivating journey of transformation and serenity in Zen Koi Classic, the enchanting mobile game where you experience the vibrancy and breathtaking beauty of the graceful Koi. Immerse yourself in a calming atmosphere filled with soothing music and mesmerizing visuals as you nurture these magnificent fish, witnessing their growth and culminating metamorphosis into majestic dragons. Unwind and Ascend: A Timeless Tale Zen Koi Classic offers a unique experience that blends relaxation with strategic collection. Breed, collect and discover beautiful Koi: witness the captivating journey of your Koi as they evolve from tiny hatchlings into breathtaking creatures, each boasting unique colors and intricate patterns. Guide them through their life cycle, culminating in a stunning transformation that embodies the legend of the Koi's ascension into a dragon. Features: Free-to-Play: Enjoy the core gameplay experience without any purchase required. Soothing and Intuitive Gameplay: Immerse yourself in a world of tranquility with simple controls and a serene environment. Unique Flowing Action: Guide your Koi with a single touch, mimicking their graceful movements through the water. A Calming Oasis: Find peace in the beautiful aquatic environment, enhanced by soothing music and sound effects. Unveiling a Spectrum of Koi: Discover and collect hundreds of stunning Koi varieties, each boasting unique color combinations and patterns. Some rare specimens await the most dedicated collectors! Share Your Passion: Share and gift magnificent Koi you have bred and collected with friends and fellow players. Limited Edition Reward: Collect and complete all Koi and Dragon collections in Zen Koi Classic and claim unique decorations for your personal pond and aquarium in Zen Koi 2 as a special bonus! Unveiling the Depths of Zen Koi Classic: A Visual Symphony: Immerse yourself in an underwater world teeming with vibrant life with plenty of prey to catch. The Calming Symphony: Escape the daily grind with a serene soundtrack by Kiat from System Sovereign featuring gentle melodies and calming ambient sounds. Soundscapes are designed by IMBA to further enhance the sense of tranquility. The Emotional Connection: Witness the heartwarming growth and transformation of your Koi. Observe their vibrant colors and discover a progression of beautiful patterns, building a special bond with your pond companions. As they evolve into majestic dragons, experience a sense of accomplishment for nurturing them throughout their journey. Download Zen Koi Classic today and embark on a captivating odyssey of transformation and tranquility! Note: Zen Koi is free to download and play. However, optional items are available via In-App Purchase within the game to expand upon your gameplay experience. By downloading this game, you agree to our Terms of Service & Privacy Policy: http://www.landsharkgames.com/terms-of-service/ http://www.landsharkgames.com/privacy-policy/ Rated 3+ by the Indonesia Game Rating System (IGRS).

About

Aquarium Fish vs Alien

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
Currently charting
Read full description

Start your aquatic adventure! - Begin each level with two guppies and other aquatic creatures, quirky pets, and surprising challenges. Feed your fish, collect coins, and unlock powerful upgrades - from better food to alien-zapping lasers! Play your way with different game modes: - Adventure Mode: Progress through 4 unique tanks and hatch 24 adorable pets to help you along the way. - Challenge Mode: Test your skills and strategy under pressure. - Virtual Tank: Build and customize your very own aquarium with shells earned in bonus rounds. With a mix of pet simulation, action, strategy, and puzzles, this game is as relaxing as it is exciting. Keep your fish happy, protect your tank, and enjoy the simple joy of your very own aquarium!

Screenshots

Zen Koi Classic4 screens
Aquarium Fish vs Alien4 screens

Verdict

The call

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.

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

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 3 months. The most recent releases landed on October 26, 2026 and October 27, 2026 respectively.

Scorecard8 real differences · 3 level
Zen Koi Classic versus Aquarium Fish vs Alien: the parameters behind the verdict, then further details
ParameterZen Koi ClassicAquarium Fish vs Alien
PriceFree — better$4.99
Rating4.7 (2.1K ratings) — better4.4 (16 ratings)
Positive reviews85.6% of reviews — better81.8% of reviews
Number of ratings2.1K — better16
Update frequencyEvery 3 monthsEvery 3 months
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
Best chart rank—#200 — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.013.0 — better
Further details — not scored
Size128 MB336 MB
Age rating4+12+
DeveloperLandShark Games Pte. Ltd.Luan Nguyen

Customer experience

Zen Koi Classic

All ratings2,057 ratings
Positive93.1%
Neutral3.8%
Negative3.1%
Written reviews383 reviews
Positive85.6%
Neutral7.6%
Negative6.8%

Aquarium Fish vs Alien

All ratings16 ratings
Positive87.5%
Neutral0.0%
Negative12.5%
Written reviews11 reviews
Positive81.8%
Neutral9.1%
Negative9.1%

Bugs and requests

Zen Koi Classic

Reported bugs

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

Requested features

5 requests
  • 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

Not enough reviews yet to summarise bugs or requests.

In-app purchases

10 purchases

Zen Koi Classic

One-time10
  • Starter Pack$1.99
  • Small Handful of pearls$1.99
  • Handful of pearls$4.99
Show 7 more
  • Hasu Pack$4.99
  • Bag of pearls$9.99
  • Tenshi Pack$9.99
  • Splatto Pack$9.99
  • Yajiri Pack$9.99
  • Monkī Pack$19.99
  • Nami Pack$19.99
None

Aquarium Fish vs Alien

No in-app purchases

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 26, 2026 and Aquarium Fish vs Alien on October 27, 2026.

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