# Helix Protocol vs Evil Ducks Castle

The clearest difference is price: Helix Protocol at Free against Evil Ducks Castle's $0.99. Helix Protocol also leads on update cadence (every 3 weeks vs every 37 months). Evil Ducks Castle's advantage is in-app purchases (none vs 7) and ads (none vs shown).

Helix Protocol is free to download; Evil Ducks Castle costs $0.99 up front. Helix Protocol sells 7 one-off in-app purchases. Evil Ducks Castle asks for nothing beyond the download.

Helix Protocol ships an update every 3 weeks, Evil Ducks Castle every 37 months. Both last shipped on October 8, 2026.

## The numbers

| Metric | Helix Protocol | Evil Ducks Castle |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 3 weeks** | Every 37 months |
| Size | 45 MB | 21 MB |
| Requires iOS | 16.0 | **12.2** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 9+ | 4+ |
| Developer | [Oleksii Poliakov](https://appshunter.io/developer/648955741) | [Anthony Hindle](https://appshunter.io/developer/1057765652) |

## What reviewers say

### Helix Protocol

[App page](https://appshunter.io/ios/app/helix-protocol/id936490163)

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 50K Credits | $2.99 | one-time |
| 125K Credits | $5.99 | one-time |
| 175K Credits | $8.99 | one-time |
| 250K Credits | $12.99 | one-time |
| 500K Credits | $19.99 | one-time |
| 750K Credits | $24.99 | one-time |
| 1M Credits | $29.99 | one-time |


### Evil Ducks Castle

[App page](https://appshunter.io/ios/app/evil-ducks-castle/id1117589870)

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

**In-app purchases:** none


## Frequently asked questions

### Is Helix Protocol free?

Helix Protocol is free to download, with in-app purchases available.

### Is Evil Ducks Castle free?

Evil Ducks Castle costs $0.99, with no in-app purchases.

### Do Helix Protocol or Evil Ducks Castle have ads?

Helix Protocol shows ads; Evil Ducks Castle does not.

### Which is updated more often, Helix Protocol or Evil Ducks Castle?

Helix Protocol ships an update every 3 weeks, and Evil Ducks Castle every 37 months. Most recently, Helix Protocol was updated on October 8, 2026 and Evil Ducks Castle on October 8, 2026.

---

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