# Mars Mystery vs Photo Differences Old Castles

The clearest difference is in-app purchases: Photo Differences Old Castles at none against Mars Mystery's 5. Photo Differences Old Castles also leads on update cadence (monthly vs every 11 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Mars Mystery sells 5 one-off in-app purchases. Photo Differences Old Castles asks for nothing beyond the download.

Mars Mystery ships an update every 11 months, Photo Differences Old Castles monthly. The most recent releases landed on October 23, 2026 and October 19, 2026 respectively.

## The numbers

| Metric | Mars Mystery | Photo Differences Old Castles |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (620 ratings)](https://appshunter.io/ios/app/mars-mystery-hidden-objects/id1577196255/reviews)** | — |
| Number of ratings | **620** | — |
| Positive reviews | 63.6% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | Yes |
| Update frequency | Every 11 months | **Monthly** |
| Monetization | Free with in-app purchases | — |
| Size | 123 MB | 79 MB |
| Requires iOS | 12.0 | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Crisp App Studio](https://appshunter.io/developer/1143551614) | [Adrijana Jakovljevic](https://appshunter.io/developer/1486022934) |

## What reviewers say

### Mars Mystery

[App page](https://appshunter.io/ios/app/mars-mystery-hidden-objects/id1577196255)

Embark on a thrilling hidden object adventure on Mars. Explore its mysterious landscapes, uncover the secrets of failed expeditions, and race back to Earth. This game offers a unique sci-fi plot and trains your eyes and mind.

**Highlights:** Hidden object gameplay, Explore Mars locations, Sci-fi plot, Hints for beginners, Replayable scenes, Eyes and mind training

**Features:** Vision Pro support

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Preview Hints Pack | $0.99 | one-time |
| NoAds | $0.99 | one-time |
| Time Machine | $0.99 | one-time |
| Instant Hint | $0.99 | one-time |
| Gold Master | $2.99 | one-time |

**What reviewers like**

- 🎨 Beautiful graphics and visual design
- 💡 Innovative hidden object gameplay with unique theme
- 🌍 Educational language learning feature
- 👍 Responsive developer that listens to player feedback
- ⭐ Engaging and enjoyable gameplay experience

**What reviewers complain about**

- 📺 Excessive and inappropriate advertisements
- 😤 Overly difficult star achievement system
- 🔄 Game progression bugs causing scene resets
- ⏱️ Limited content length

**Reported bugs**

- Skip ad button not functioning properly
- Scene reversion to jungle/animal scenes without clear objectives
- Three-star achievement system not triggering despite repeated play
- Hint system required to progress past certain scenes

**Requested features**

- Longer gameplay with more levels
- Better ad filtering for family-friendly content
- Improved star achievement mechanics clarity


### Photo Differences Old Castles

[App page](https://appshunter.io/ios/app/photo-differences-old-castles/id1664135973)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Mars Mystery free?

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

### Is Photo Differences Old Castles free?

Photo Differences Old Castles is free to download, with no in-app purchases.

### Do Mars Mystery or Photo Differences Old Castles have ads?

Both Mars Mystery and Photo Differences Old Castles show ads.

### Which is updated more often, Mars Mystery or Photo Differences Old Castles?

Mars Mystery ships an update every 11 months, and Photo Differences Old Castles monthly. Most recently, Mars Mystery was updated on October 23, 2026 and Photo Differences Old Castles on October 19, 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.*