Comparison

circloO vs Quantum Defender

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

Head to head
About

circloO

A colorful physics platformer where you guide a ball through growing circular levels. Collect circles to expand the play area, strategically using and avoiding obstacles. Discover unique physics mechanics and enjoy a vast collection of player-created levels.

Highlights
  • Circular physics puzzles
  • Level editor
  • Player-created levels
  • Unique physics mechanics
  • Growing levels
  • Hard Mode levels
Read full description

circloO is a colorful physics platformer in a growing circle. This app version contains all levels from circloO and circloO 2, plus brand-new bonus levels! There's also a level editor and already over 10,000 levels created by players like you! You're a small ball rolling around in a round level. Collect circles to grow the level circle. As it grows, everything stays in the level, so you'll have to avoid and use obstacles in everchanging ways. For example, a platform that was first very useful to gain height, may prove to be a challenging obstacle after the level has grown! You can only move left and right, so you'll want to use features of the level carefully to jump and gain height. You'll discover all sorts of physics features, such as changing gravity, a sea of tiny blocks, strange contraptions and even planets with a gravity field. In challenging parts, you'll find yourself fully immersed, pressing the screen as hard as you can trying to get closer to finally collecting that next circle. But don't worry: you'll never have to start over a level, so you can always try again really quickly! And I can guarantee you'll feel amazing once you finally manage it! circloO Complete features: - Lots of cool physics features: ropes, pulleys, changing gravity and much more! I've included quite a few mechanics for you to discover. - Over 75 fun, growing, ever more challenging levels! Can you complete the six almost-but-not-quite-impossible Hard Mode levels? - There's also a level editor and an ever increasing number of player created levels! - All levels from circloO 2 and the original circloO, plus 28 brand-new levels! - Unique physics puzzles in each level. - Great music and sound effects by Stijn Cappetijn. - Minimalist and colorful graphics. - The game will take most players three to five hours to complete. Level times are saved, so you can try to beat your own highscores and speedrun levels after that! Plus there are thousands of player-created levels to continue playing forever! - Relaxing yet challenging physics puzzle platforming fun! I'm very happy that circloO 2 on the web won the first Crazy Games developer contest out of 200 contestants! It was also third in the Kongregate contest of November 2018. You may remember it from CoolMath Games as well. Reviews: "It’s an excellent game that has a very playful and chilled out approach to the gameplay, whilst also featuring some wonderfully intricate level design. A very impressive puzzle platformer you’ll really want to roll with. Highly recommended." - Free Game Planet "The difficulty scales upwards nicely and you're constantly rewarded for learning new skills as these always come up in future levels." - Jayisgames The game contains occasional ads after a level, which can be removed with a one-time in-app purchase, which supports development as well. Have fun and I'm happy to hear what you think!

About

Quantum Defender

Defend a quantum core by controlling and aligning a wavefunction against waves of incoming enemies. This arcade action game transforms abstract quantum concepts into fast-paced, visual gameplay with simple touch controls and escalating challenges.

Highlights
  • Fast arcade defense gameplay
  • Wavefunction alignment mechanics
  • Quantum-inspired enemies and effects
  • Increasing enemy pressure
  • Designed for touch controls
  • Sci-fi wave-based game world
Features
Read full description

Quantum Defender is an arcade action game where you defend a quantum core by controlling and aligning a wavefunction against incoming enemies. Rotate, time, and lock your quantum state into the right orientation to stop threats before they reach the center. Each encounter turns abstract quantum ideas into fast visual gameplay: alignment, phase, resonance, shields, targets, and energy bursts become part of the action. Built for quick play sessions, Quantum Defender combines simple touch controls with escalating enemy pressure and bright sci-fi visuals. Features: • Fast arcade defense gameplay • Wavefunction alignment and target-lock mechanics • Quantum-inspired enemies, shields, and energy effects • Increasing pressure as enemies close in • Designed for touch controls on iPhone and iPad • A science-inspired game world built around waves, phase, and resonance Quantum Defender is a game, not a physics textbook. It uses quantum-inspired visuals and mechanics to make wave alignment feel active, playful, and exciting.

Screenshots

circloO4 screens
Quantum Defender4 screens

Verdict

The call

The clearest difference is ads: Quantum Defender at none against circloO's shown. Quantum Defender also leads on update cadence (every 6 days vs every 2 months). circloO's advantage is ratings volume (2.4K vs 1) and iOS requirement (10 vs 15.0). On price, rating, in-app purchases and monetization model 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. circloO sells 1 one-off in-app purchase and Quantum Defender sells 7 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

Quantum Defender holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: circloO has 2.4K ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

circloO ships an update every 2 months, Quantum Defender every 6 days. The most recent releases landed on October 10, 2026 and October 2, 2026 respectively.

Scorecard4 real differences · 6 level
circloO versus Quantum Defender: the parameters behind the verdict, then further details
ParametercircloOQuantum Defender
PriceFreeFree
Rating4.8 (2.4K ratings)5.0 (1 ratings) — better
Positive reviews89.5% of reviews—
Number of ratings2.4K — better1
Update frequencyEvery 2 monthsEvery 6 days — better
AdsYesNo — better
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS10 — better15.0
Further details — not scored
Size63 MB124 MB
Age rating4+4+
DeveloperFlorian van StrienRQM Technologies LLC

Customer experience

circloO

All ratings2,357 ratings
Positive96.9%
Neutral1.4%
Negative1.7%
Written reviews133 reviews
Positive89.5%
Neutral3.0%
Negative7.5%

Quantum Defender

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

circloO

Reported bugs

2 issues
  • Glitches with level progression
  • Inconsistent touch/click registration

Requested features

4 requests
  • More levels and content updates
  • Character customization options
  • Improved level editor tools
  • Difficulty settings or options

Quantum Defender

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

circloO

One-time1
  • Remove Ads$2.99
7 purchases

Quantum Defender

One-time7
  • Cadet Qubit Pack$1.99
  • Field Qubit Pack$5.99
  • Command Qubit Pack$11.99
Show 4 more
  • Singularity Qubit Pack$25.99
  • Architect Qubit Pack$49.99
  • Navigator Qubit Pack$99.99
  • Horizon Qubit Pack$199.99

Questions

Is circloO free?
circloO is free to download, with in-app purchases available.
Is Quantum Defender free?
Quantum Defender is free to download, with in-app purchases available.
Which has better reviews, circloO or Quantum Defender?
Quantum Defender is rated higher. circloO averages 4.8 out of 5 from 2.4K ratings, while Quantum Defender averages 5.0 from 1 ratings.
Do circloO or Quantum Defender have ads?
circloO shows ads; Quantum Defender does not.
Which is updated more often, circloO or Quantum Defender?
circloO ships an update every 2 months, and Quantum Defender every 6 days. Most recently, circloO was updated on October 10, 2026 and Quantum Defender on October 2, 2026.

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