# Space Tower vs Backpack Merge

The clearest difference is ads: Backpack Merge at none against Space Tower's shown. Space Tower's advantage is rating (4.8 vs 4.4) and review sentiment (40% vs 25%). On price, update cadence, in-app purchases and monetization model there is nothing between them.

Both are free to download. Space Tower sells 21 one-off in-app purchases and Backpack Merge sells 44 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Space Tower holds the better App Store score, 4.8 against 4.4. Both are backed by a comparable volume of ratings — 571 and 119 respectively. Written reviews point the same way: 40% of Space Tower's written reviews are positive against 25% of Backpack Merge's.

Space Tower ships an update every 5 weeks, Backpack Merge every 6 weeks. The most recent releases landed on October 23, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Space Tower | Backpack Merge |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (571 ratings)](https://appshunter.io/ios/app/space-tower-galaxy-tower-td/id1672563510/reviews)** | [4.4 (119 ratings)](https://appshunter.io/ios/app/backpack-merge/id6566180728/reviews) |
| Number of ratings | **571** | 119 |
| Positive reviews | **40.0% of reviews** | 25.4% of reviews |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | **Every 5 weeks** | Every 6 weeks |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 190 MB | 231 MB |
| Requires iOS | 13.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 9+ |
| Developer | [CYBERJOY LIMITED](https://appshunter.io/developer/1602455961) | [伟 王](https://appshunter.io/developer/1403717237) |

## What reviewers say

### Space Tower

[App page](https://appshunter.io/ios/app/space-tower-galaxy-tower-td/id1672563510)

Command a galactic defense to protect your space tower from alien invaders. Strategically upgrade your tower's abilities and weapons to withstand relentless waves of enemies and defeat powerful bosses. Enjoy idle gameplay with ample rewards, even while offline.

**Highlights:** Idle tower defense gameplay, Strategic tower defense, Upgrade basic abilities, Activate powerful weapons, Unlock and improve tech abilities, Defend against alien attacks, Battle mighty bosses

**Features:** macOS Compatibility

**In-app purchases (21)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Newbie Pack | $2.99 | one-time |
| Chapter Pack | $2.99 | one-time |
| Special Pack 1 | $2.99 | one-time |
| Tournament Pack 1 | $2.99 | one-time |
| Pouch Of Diamonds | $4.99 | one-time |
| Chapter Pack | $4.99 | one-time |
| Special Pack 2 | $4.99 | one-time |
| Piggy Bank | $4.99 | one-time |
| Tournament Pack 2 | $4.99 | one-time |
| VIP Pack | $9.99 | one-time |
| Chapter Pack 3 | $9.99 | one-time |
| Special Pack 3 | $9.99 | one-time |
| Month Card | $9.99 | one-time |
| Tournament Pack 3 | $9.99 | one-time |
| Original Price Price 10.99 | $10.99 | one-time |
| Resource Pack | $14.99 | one-time |
| Original Price Price 17.99 | $17.99 | one-time |
| Special Pack 4 | $19.99 | one-time |
| Tournament Pack 4 | $19.99 | one-time |
| Premium Resource Pack | $29.99 | one-time |
| Original Price Price 79.99 | $79.99 | one-time |

**What reviewers like**

- 🎮 Engaging and addictive gameplay mechanics
- ⬆️ Extensive upgrade and progression systems
- 🎨 Visually appealing design
- ⏱️ Good for casual play between other activities

**What reviewers complain about**

- 💰 Aggressive monetization and pay-to-win mechanics
- ⚡ Energy system limits gameplay
- 🐛 Data synchronization failures across devices
- 🔄 Repetitive grinding required
- ⏳ Excessively long research/upgrade timers

**Reported bugs**

- Game freezes and fails to load progress data
- Data not syncing between devices with same Apple ID
- Ad-free purchases requiring repurchase on new devices
- Tournament upgrade buffs not applying correctly
- Research timer displaying incorrect duration (30 minutes showing as 31 hours)

**Requested features**

- More game levels
- Additional weapons and enemy variety
- Restore previously available game formats (Galaxy Background, Flaming Eye)
- Remove or reduce energy system
- Improve gold generation rates


### Backpack Merge

[App page](https://appshunter.io/ios/app/backpack-merge/id6566180728)

Merge magical equipment and strategically organize your backpack to defend a peaceful academy from a monster invasion. Become the legendary Archmage and discover diverse combat strategies through talented equipment combinations.

**Highlights:** Merge equipment, Organize backpack, Defend from monsters, Diverse strategies, Talented equipment combinations

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

**In-app purchases (44)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Package47 | $0.99 | one-time |
| Some Gems | $0.99 | one-time |
| Package65 | $0.99 | one-time |
| Package54 | $0.99 | one-time |
| Package61 | $0.99 | one-time |
| Package33 | $0.99 | one-time |
| Package40 | $0.99 | one-time |
| Package26 | $0.99 | one-time |
| Package9 | $0.99 | one-time |
| Package11 | $0.99 | one-time |
| Package27 | $1.99 | one-time |
| Package71 | $4.99 | one-time |
| Package72 | $4.99 | one-time |
| Package144 | $4.99 | one-time |
| Package141 | $4.99 | one-time |
| A small pile of gems | $4.99 | one-time |
| Package7 | $4.99 | one-time |
| Package12 | $4.99 | one-time |
| Package28 | $4.99 | one-time |
| Package35 | $4.99 | one-time |
| Package21 | $4.99 | one-time |
| Package76 | $6.99 | one-time |
| Package80 | $7.99 | one-time |
| Package81 | $7.99 | one-time |
| Package86 | $8.99 | one-time |
| Package84 | $8.99 | one-time |
| Package181 | $9.99 | one-time |
| Package90 | $9.99 | one-time |
| Package43 | $9.99 | one-time |
| Package50 | $9.99 | one-time |
| Package14 | $9.99 | one-time |
| Package36 | $9.99 | one-time |
| A large pile of gems | $9.99 | one-time |
| Package22 | $9.99 | one-time |
| Package8 | $9.99 | one-time |
| Package10 | $9.99 | one-time |
| Package13 | $9.99 | one-time |
| Package204 | $14.99 | one-time |
| Package102 | $15.99 | one-time |
| Package103 | $15.99 | one-time |
| Package23 | $19.99 | one-time |
| A bag of gems | $19.99 | one-time |
| Package44 | $19.99 | one-time |
| Package24 | $49.99 | one-time |

**What reviewers like**

- 🎮 Engaging and addictive gameplay mechanics
- 🎨 Attractive art style and visual design
- 🧠 Strategic depth with resource management
- ⚡ Active developer support with regular patches
- 🎯 Unique backpack/inventory management concept

**What reviewers complain about**

- 📺 Excessive ad frequency and duration (90+ seconds)
- 💰 Extremely high monetization and pay-to-win mechanics
- 🐛 Frequent server connection errors and crashes
- ⚠️ Ads frequently fail to load properly
- ⚖️ Severe game balance issues (weak weapons, overpowered enemies)

**Reported bugs**

- Ads fail to load or display (critical issue affecting rewards)
- Server connection errors and timeouts
- Insufficient items equipped error blocking stage progression
- Stamina randomly drains after server errors
- Login failures with Facebook and Apple ID

**Requested features**

- Add German language support
- Add Ukrainian and Russian language options
- Add Google ID login option for iOS
- Reduce ad frequency and duration
- Implement alternative monetization model


## Frequently asked questions

### Is Space Tower free?

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

### Is Backpack Merge free?

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

### Which has better reviews, Space Tower or Backpack Merge?

Space Tower is rated higher. Space Tower averages 4.8 out of 5 from 571 ratings, while Backpack Merge averages 4.4 from 119 ratings.

### Do Space Tower or Backpack Merge have ads?

Space Tower shows ads; Backpack Merge does not.

### Which is updated more often, Space Tower or Backpack Merge?

Space Tower ships an update every 5 weeks, and Backpack Merge every 6 weeks. Most recently, Space Tower was updated on October 23, 2026 and Backpack Merge on October 24, 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.*