# Merge Loop vs Rat Killer Robot Invasion

The clearest difference is in-app purchases: Merge Loop at none against Rat Killer Robot Invasion's 17. Rat Killer Robot Invasion's advantage is update cadence (every 10 days vs monthly). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Rat Killer Robot Invasion sells 17 in-app purchases, starting at $4.99 per 7 days. Merge Loop asks for nothing beyond the download.

Merge Loop ships an update monthly, Rat Killer Robot Invasion every 10 days. The most recent releases landed on October 13, 2026 and October 22, 2026 respectively.

## The numbers

| Metric | Merge Loop | Rat Killer Robot Invasion |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.6 (2K ratings)](https://appshunter.io/ios/app/rat-killer-robot-invasion/id6464372285/reviews)** |
| Number of ratings | — | **2K** |
| Positive reviews | — | 31.1% of reviews |
| In-app purchases | **No** | Yes |
| Ads | Yes | Yes |
| Update frequency | Monthly | **Every 10 days** |
| Monetization | — | Free with in-app purchases |
| Size | 117 MB | 353 MB |
| Requires iOS | 13.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 12+ | 9+ |
| Developer | [Full Fat Productions Ltd](https://appshunter.io/developer/374306144) | [TapNation](https://appshunter.io/developer/1483575279) |

## What reviewers say

### Merge Loop

[App page](https://appshunter.io/ios/app/merge-loop/id1642743777)

**Features:** macOS Compatibility

**In-app purchases:** none


### Rat Killer Robot Invasion

[App page](https://appshunter.io/ios/app/rat-killer-robot-invasion/id6464372285)

Embark on an epic quest to exterminate waves of invading rats with futuristic weapons. Collect in-game currency to unlock new zones, upgrade your robot companion, and customize its appearance. Explore diverse worlds and face challenging puzzles and boss battles.

**Highlights:** Rat extermination action, Robot customization, Weapon collection and upgrades, Diverse world exploration, Puzzles and boss battles, Collect money and gems

**Features:** macOS Compatibility

**In-app purchases (17)**

| Purchase | Price | Billing |
| --- | --- | --- |
| VIP Membership - Weekly | $4.99 | per 7 days |
| Elite Membership - Weekly | $8.99 | per 7 days |
| Elite Membership - Monthly | $24.99 | per month |
| Skip It - Small Pack | $0.99 | one-time |
| One Time Offer | $1.99 | one-time |
| Handful Of Crystals | $1.99 | one-time |
| Bunch Of Crystals | $4.99 | one-time |
| Skip It - Medium Pack | $8.99 | one-time |
| Pile Of Crystals | $8.99 | one-time |
| Rats Pass | $9.99 | one-time |
| Small Bundle | $11.99 | one-time |
| Master Mode | $15.99 | one-time |
| Starter Pack | $15.99 | one-time |
| Medium Bundle | $24.99 | one-time |
| Limited Offer Pack | $29.99 | one-time |
| Premium Offer | $39.99 | one-time |
| Crate Of Crystals | $89.99 | one-time |

**What reviewers like**

- 👍 Fun gameplay
- 🦂 Scorpion mech character

**What reviewers complain about**

- 🐛 Glitchy and buggy
- 🕰️ Excessive ads
- ⚠️ Imbalanced game mechanics
- 💰 Progression blocked by premium currency

**Reported bugs**

- Character flipping upside down or flying across the board
- NPCs getting stuck in portals or on walls
- Incorrect item/reward drops from chests
- Launching player off the screen
- Robot unable to keep legs on the ground and rolling around

**Requested features**

- Optimize performance and fix bugs
- Improve game balance and progression
- Add more content and features
- Provide better customer support


## Frequently asked questions

### Is Merge Loop free?

Merge Loop is free to download, with no in-app purchases.

### Is Rat Killer Robot Invasion free?

Rat Killer Robot Invasion is free to download, with in-app purchases available.

### Do Merge Loop or Rat Killer Robot Invasion have ads?

Both Merge Loop and Rat Killer Robot Invasion show ads.

### Which is updated more often, Merge Loop or Rat Killer Robot Invasion?

Merge Loop ships an update monthly, and Rat Killer Robot Invasion every 10 days. Most recently, Merge Loop was updated on October 13, 2026 and Rat Killer Robot Invasion on October 22, 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.*