# PROTOCOL vs Subterranean

The clearest difference is in-app purchases: Subterranean at none against PROTOCOL's 10. Subterranean also leads on ads (none vs shown) and iOS requirement (13.0 vs 15.0). On price, update cadence and device support there is nothing between them.

Both are free to download. PROTOCOL sells 10 one-off in-app purchases. Subterranean asks for nothing beyond the download.

PROTOCOL ships an update every 3 days, Subterranean every 2 days. The most recent releases landed on October 19, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | PROTOCOL | Subterranean |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 3 days | **Every 2 days** |
| Size | 258 MB | 142 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 9+ | 4+ |
| Developer | [SungGwon Han](https://appshunter.io/developer/1117887913) | [Tayin Wallace](https://appshunter.io/developer/1658923996) |

## What reviewers say

### PROTOCOL

[App page](https://appshunter.io/ios/app/protocol-zero-rift/id6740158945)

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Beginner Package 1 | $0.99 | one-time |
| Sale Package 3 | $1.99 | one-time |
| Sale Package 1 | $2.99 | one-time |
| Sale Package 2 | $4.99 | one-time |
| Beginner Package 2 | $4.99 | one-time |
| Remove Ad | $5.99 | one-time |
| Daily Special Mission Ticket | $7.99 | one-time |
| Mission Energy Booster (30 Days) | $9.99 | one-time |
| Stage Pass | $9.99 | one-time |
| Beginner Package 3 | $14.99 | one-time |


### Subterranean

[App page](https://appshunter.io/ios/app/subterranean/id6754824884)

**In-app purchases:** none


## Frequently asked questions

### Is PROTOCOL free?

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

### Is Subterranean free?

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

### Do PROTOCOL or Subterranean have ads?

PROTOCOL shows ads; Subterranean does not.

### Which is updated more often, PROTOCOL or Subterranean?

PROTOCOL ships an update every 3 days, and Subterranean every 2 days. Most recently, PROTOCOL was updated on October 19, 2026 and Subterranean on October 13, 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.*