# Stack Attack!! vs Zippy Sum

The clearest difference is in-app purchases: Zippy Sum at none against Stack Attack!!'s 19. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Stack Attack!! sells 19 one-off in-app purchases. Zippy Sum asks for nothing beyond the download.

Stack Attack!! ships an update every 2 weeks, Zippy Sum weekly. The most recent releases landed on October 22, 2026 and October 23, 2026 respectively.

## The numbers

| Metric | Stack Attack!! | Zippy Sum |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.3 (399 ratings)](https://appshunter.io/ios/app/stack-attack/id6566190313/reviews)** | — |
| Number of ratings | **399** | — |
| Positive reviews | 23.2% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | Yes |
| Update frequency | Every 2 weeks | **Weekly** |
| Monetization | Free with in-app purchases | — |
| Size | 247 MB | 27 MB |
| Requires iOS | 14.0 | 14.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 12+ | 4+ |
| Developer | [Voodoo](https://appshunter.io/developer/714804730) | [Pushkar Kathuria](https://appshunter.io/developer/1896538275) |

## What reviewers say

### Stack Attack!!

[App page](https://appshunter.io/ios/app/stack-attack/id6566190313)

Engage in intense battles against waves of enemies, strategically demolishing their formations with powerful weapons. Upgrade your capabilities by selecting the best skills to protect the cube world from a malevolent hex invasion.

**Highlights:** Defeat enemy waves, Demolish enemy stacks, Upgrade skills, Save the cube world, Space invader gameplay

**Features:** macOS Compatibility

**In-app purchases (19)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Gem Pack Small | $0.99 | one-time |
| Gold Pack Small | $0.99 | one-time |
| Starter Pack | $2.99 | one-time |
| No Ads | $2.99 | one-time |
| Gem Pack Medium | $4.99 | one-time |
| 2X Speed! | $4.99 | one-time |
| Gold Pack Medium | $4.99 | one-time |
| Skip'its Medium Pack | $5.99 | one-time |
| Gem Pack Large | $9.99 | one-time |
| Gold Pack Large | $9.99 | one-time |
| Premium Pass | $14.99 | one-time |
| Gem Pack XL | $19.99 | one-time |
| Skip'its Large Pack | $19.99 | one-time |
| Gold Pack XL | $19.99 | one-time |
| Diamond Hero | $29.99 | one-time |
| Gem Pack XXL | $49.99 | one-time |
| Gold Pack XXL | $49.99 | one-time |
| Gem Pack XXXL | $99.99 | one-time |
| Gold Pack XXXL | $99.99 | one-time |

**What reviewers like**

- 👍 Simple and fun gameplay
- 🚀 No ads or microtransactions
- 💡 Nice armor upgrade system

**What reviewers complain about**

- 🐛 Glitches and bugs, especially after updates
- 🐛 Progress and upgrades getting reset or lost
- 🐛 Levels becoming unplayable after a certain point

**Reported bugs**

- Enemies' health scaling with player's attack power
- Levels freezing or getting stuck at checkpoints
- Weapon and upgrade levels getting downgraded randomly

**Requested features**

- Mute sound effects option
- Better communication from developers about updates
- More content and stages to progress through


### Zippy Sum

[App page](https://appshunter.io/ios/app/zippy-sum/id6768092391)

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

**In-app purchases:** none


## Frequently asked questions

### Is Stack Attack!! free?

Stack Attack!! is free to download, with in-app purchases available.

### Is Zippy Sum free?

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

### Do Stack Attack!! or Zippy Sum have ads?

Both Stack Attack!! and Zippy Sum show ads.

### Which is updated more often, Stack Attack!! or Zippy Sum?

Stack Attack!! ships an update every 2 weeks, and Zippy Sum weekly. Most recently, Stack Attack!! was updated on October 22, 2026 and Zippy Sum on October 23, 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.*