# The Happiness Project vs SoilPlastic

The Happiness Project and SoilPlastic are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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

The Happiness Project ships an update every 5 months, SoilPlastic every 3 months. The most recent releases landed on November 2, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | The Happiness Project | SoilPlastic |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.9 (42 ratings)](https://appshunter.io/ios/app/the-happiness-project/id1366965114/reviews)** | — |
| Number of ratings | **42** | — |
| Positive reviews | 33.3% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 3 months** |
| Monetization | Free | — |
| Size | 99 MB | 122 MB |
| Requires iOS | 13.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 12+ | 4+ |
| Developer | [UCL](https://appshunter.io/developer/611203777) | [SPOTTERON Gmbh](https://appshunter.io/developer/1378099707) |

## What reviewers say

### The Happiness Project

[App page](https://appshunter.io/ios/app/the-happiness-project/id1366965114)

Engage in short, enjoyable mini-games designed by scientists to contribute to real psychological and neuroscience research. Your gameplay and anonymous survey responses help study well-being, anxiety, and depression.

**Highlights:** Play mini-games for science, Contribute to psychology research, Study neuroscience of well-being, Anonymous surveys, Understand mental health, Citizen science project

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

**In-app purchases:** none


### SoilPlastic

[App page](https://appshunter.io/ios/app/soilplastic/id1622415639)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is The Happiness Project free?

The Happiness Project is free to download, with no in-app purchases.

### Is SoilPlastic free?

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

### Do The Happiness Project or SoilPlastic have ads?

Neither The Happiness Project nor SoilPlastic shows ads.

### Which is updated more often, The Happiness Project or SoilPlastic?

The Happiness Project ships an update every 5 months, and SoilPlastic every 3 months. Most recently, The Happiness Project was updated on November 2, 2026 and SoilPlastic on October 4, 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.*