# Backpack Tower Defense vs Space Outpost

The clearest difference is in-app purchases: Space Outpost at none against Backpack Tower Defense's 8. Space Outpost also leads on update cadence (daily vs weekly). Backpack Tower Defense's advantage is device support (3 vs 1). On price, ads and iOS requirement there is nothing between them.

Both are free to download. Backpack Tower Defense sells 8 one-off in-app purchases. Space Outpost asks for nothing beyond the download.

Backpack Tower Defense ships an update weekly, Space Outpost daily. The most recent releases landed on October 18, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Backpack Tower Defense | Space Outpost |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/space-outpost/id6772625531/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | Yes | Yes |
| Update frequency | Weekly | **Daily** |
| Monetization | — | Ad-supported |
| Size | 175 MB | 78 MB |
| Requires iOS | **15.0** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 12+ |
| Developer | [Ngo Nguyen](https://appshunter.io/developer/1833419289) | [Steven Brown](https://appshunter.io/developer/1896142200) |

## What reviewers say

### Backpack Tower Defense

[App page](https://appshunter.io/ios/app/backpack-tower-defense/id6762122942)

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

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Spark Gems | $1.99 | one-time |
| Boost Gems | $3.99 | one-time |
| Remove ads | $4.99 | one-time |
| Starter Pack | $4.99 | one-time |
| Power Gems | $7.99 | one-time |
| Elite Gems | $17.99 | one-time |
| Master Gems | $34.99 | one-time |
| Infinity Gems | $79.99 | one-time |


### Space Outpost

[App page](https://appshunter.io/ios/app/space-outpost/id6772625531)

Defend your outpost against relentless alien hordes in this sci-fi tower defense game. Strategically build and upgrade defensive towers, deploy mobile units, and utilize powerful orbital strikes to save the sun. Play offline and one-handed.

**Highlights:** Campaign across unique planets, Diverse tower and unit types, Mobile strike units and orbital powerups, Multiple enemy types and bosses, Classic and Sudden Death game modes, Offline and one-handed play, Unlockable towers, units, and powerups

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

**In-app purchases:** none


## Frequently asked questions

### Is Backpack Tower Defense free?

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

### Is Space Outpost free?

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

### Do Backpack Tower Defense or Space Outpost have ads?

Both Backpack Tower Defense and Space Outpost show ads.

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

Backpack Tower Defense ships an update weekly, and Space Outpost daily. Most recently, Backpack Tower Defense was updated on October 18, 2026 and Space Outpost on October 10, 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.*