# Circular Defense vs Zenith Tower

The clearest difference is in-app purchases: Circular Defense at none against Zenith Tower's 10. Circular Defense also leads on iOS requirement (8.0 vs 15.0). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Zenith Tower sells 10 one-off in-app purchases. Circular Defense asks for nothing beyond the download.

Circular Defense ships an update every 2 days, Zenith Tower every 3 days. The most recent releases landed on November 2, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | Circular Defense | Zenith Tower |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.4 (8 ratings)](https://appshunter.io/ios/app/circular-defense/id1410103026/reviews)** | — |
| Number of ratings | **8** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 days** | Every 3 days |
| Monetization | Free | — |
| Size | 124 MB | 132 MB |
| Requires iOS | **8.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 12+ |
| Developer | [Picola Inc.](https://appshunter.io/developer/983881487) | [Christian Brown](https://appshunter.io/developer/1896708359) |

## What reviewers say

### Circular Defense

[App page](https://appshunter.io/ios/app/circular-defense/id1410103026)

Engage in a unique tower defense experience where enemies approach the core from all sides. Strategically place and upgrade circular turrets to defend your position across over 50 challenging stages. Enjoy a smooth, time-killing gameplay with simple controls and deep strategic possibilities.

**Highlights:** Unique circular turret defense, Strategic placement and upgrades, Over 50 challenging stages, Easy to operate controls, Smooth, time-killing gameplay

**Features:** macOS Compatibility

**In-app purchases:** none


### Zenith Tower

[App page](https://appshunter.io/ios/app/zenith-tower-idle-defense/id6770016221)

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Daily Cache - 400 Gems | $0.49 | one-time |
| Starter Cache - 1,200 Gems | $1.95 | one-time |
| Quick Deal | $1.99 | one-time |
| Value Deal | $4.99 | one-time |
| Super Deal | $9.99 | one-time |
| Big Deal | $19.99 | one-time |
| 7,000 Gems (2,000 Bonus) | $29.99 | one-time |
| Huge Deal | $29.99 | one-time |
| Mega Deal | $49.99 | one-time |
| 32,000 Gems (12,000 Bonus) | $129.99 | one-time |


## Frequently asked questions

### Is Circular Defense free?

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

### Is Zenith Tower free?

Zenith Tower is free to download, with in-app purchases available.

### Do Circular Defense or Zenith Tower have ads?

Neither Circular Defense nor Zenith Tower shows ads.

### Which is updated more often, Circular Defense or Zenith Tower?

Circular Defense ships an update every 2 days, and Zenith Tower every 3 days. Most recently, Circular Defense was updated on November 2, 2026 and Zenith Tower on October 28, 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.*