# Space Bubble Puzzle vs Retro Block Duo

The clearest difference is update cadence: Retro Block Duo at fortnightly against Space Bubble Puzzle's monthly. Space Bubble Puzzle's advantage is iOS requirement (12.0 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Space Bubble Puzzle ships an update monthly, Retro Block Duo fortnightly. The most recent releases landed on October 13, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | Space Bubble Puzzle | Retro Block Duo |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | Yes | Yes |
| Update frequency | Monthly | **Fortnightly** |
| Size | 136 MB | 15 MB |
| Requires iOS | **12.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Yuta Kamiya](https://appshunter.io/developer/1760454275) | [咏武 王](https://appshunter.io/developer/486171035) |

## What reviewers say

### Space Bubble Puzzle

[App page](https://appshunter.io/ios/app/space-bubble-puzzle/id6596733728)

**In-app purchases:** none


### Retro Block Duo

[App page](https://appshunter.io/ios/app/retro-block-duo/id6746492282)

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

**In-app purchases:** none


## Frequently asked questions

### Is Space Bubble Puzzle free?

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

### Is Retro Block Duo free?

Retro Block Duo is free to download, with no in-app purchases.

### Do Space Bubble Puzzle or Retro Block Duo have ads?

Both Space Bubble Puzzle and Retro Block Duo show ads.

### Which is updated more often, Space Bubble Puzzle or Retro Block Duo?

Space Bubble Puzzle ships an update monthly, and Retro Block Duo fortnightly. Most recently, Space Bubble Puzzle was updated on October 13, 2026 and Retro Block Duo on October 12, 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.*