# RobotVSAlien vs Otter Forest　～Idle Game～

The clearest difference is rating: RobotVSAlien at 4.0 against Otter Forest　～Idle Game～'s 1.5. RobotVSAlien also leads on update cadence (every 2 weeks vs every 6 months) and iOS requirement (7.0 vs 11.0). Otter Forest　～Idle Game～'s advantage is in-app purchases (none vs 1). On price, ratings volume, ads and device support there is nothing between them.

Both are free to download. RobotVSAlien sells 1 one-off in-app purchase. Otter Forest　～Idle Game～ asks for nothing beyond the download.

RobotVSAlien holds the better App Store score, 4.0 against 1.5. Both are backed by a comparable volume of ratings — 1 and 2 respectively.

RobotVSAlien ships an update every 2 weeks, Otter Forest　～Idle Game～ every 6 months. The most recent releases landed on October 21, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | RobotVSAlien | Otter Forest　～Idle Game～ |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.0 (1 ratings)](https://appshunter.io/ios/app/robotvsalien/id863067072/reviews)** | [1.5 (2 ratings)](https://appshunter.io/ios/app/otter-forest-idle-game/id1474195298/reviews) |
| Number of ratings | 1 | **2** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Every 6 months |
| Monetization | Free with in-app purchases | **Free** |
| Size | 55 MB | 58 MB |
| Requires iOS | **7.0** | 11.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 12+ | 4+ |
| Developer | [Akihiro Fujiwara](https://appshunter.io/developer/721031264) | [minoru yamazaki](https://appshunter.io/developer/1449437588) |

## What reviewers say

### RobotVSAlien

[App page](https://appshunter.io/ios/app/robotvsalien/id863067072)

Defend against alien invaders using a growing army of robots. This casual defense game allows players to upgrade and promote their units to increase their strength. Design your own giant robot and repel the alien threat.

**Highlights:** Casual defense gameplay, Unit promotion and upgrading, Design giant robots, Repel alien invaders, Unique robot and alien designs

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads and Privilege granting | $0.99 | one-time |


### Otter Forest　～Idle Game～

[App page](https://appshunter.io/ios/app/otter-forest-idle-game/id1474195298)

Collect adorable and unique otters in this idle game. Improve the forest environment to attract more animals and complete your picture book. Interact with the otters to uncover their stories and enjoy healing gameplay during your free time.

**Highlights:** Collect unique otters, Improve forest environment, Complete picture book, Interact with otters for stories, Idle gameplay, Easy operation and simple rules

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is RobotVSAlien free?

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

### Is Otter Forest　～Idle Game～ free?

Otter Forest　～Idle Game～ is free to download, with no in-app purchases.

### Which has better reviews, RobotVSAlien or Otter Forest　～Idle Game～?

RobotVSAlien is rated higher. RobotVSAlien averages 4.0 out of 5 from 1 ratings, while Otter Forest　～Idle Game～ averages 1.5 from 2 ratings.

### Do RobotVSAlien or Otter Forest　～Idle Game～ have ads?

Neither RobotVSAlien nor Otter Forest　～Idle Game～ shows ads.

### Which is updated more often, RobotVSAlien or Otter Forest　～Idle Game～?

RobotVSAlien ships an update every 2 weeks, and Otter Forest　～Idle Game～ every 6 months. Most recently, RobotVSAlien was updated on October 21, 2026 and Otter Forest　～Idle Game～ on October 5, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*