# What the Shell vs Zero21 Card Game

The clearest difference is review sentiment: What the Shell at 100% against Zero21 Card Game's 0%. What the Shell also leads on rating (5.0 vs 4.0) and ads (none vs shown). On price, ratings volume, 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.

What the Shell holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 6 and 3 respectively. Written reviews point the same way: 100% of What the Shell's written reviews are positive against 0% of Zero21 Card Game's.

What the Shell ships an update every 8 days, Zero21 Card Game every 65 months. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | What the Shell | Zero21 Card Game |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (6 ratings)](https://appshunter.io/ios/app/what-the-shell/id925447970/reviews)** | [4.0 (3 ratings)](https://appshunter.io/ios/app/zero21-card-game/id1550265606/reviews) |
| Number of ratings | **6** | 3 |
| Positive reviews | **100.0% of reviews** | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | **Every 8 days** | Every 65 months |
| Monetization | **Free** | Ad-supported |
| Size | 138 MB | 58 MB |
| Requires iOS | 16.0 | **15.6** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Chuck Smith](https://appshunter.io/developer/290402113) | [Le Nhung](https://appshunter.io/developer/1436505077) |

## What reviewers say

### What the Shell

[App page](https://appshunter.io/ios/app/what-the-shell/id925447970)

Experience a unique twist on a classic board game where both players move simultaneously and secretly. Outwit your opponent by capturing pieces, hatching eggs, and strategically lining up five in a row. Enjoy face-to-face play, online matches, or offline challenges.

**Highlights:** Simultaneous secret moves, Piece capture mechanics, Egg hatching and capture, Local and online multiplayer, Offline AI opponent, Controller support

**Features:** macOS Compatibility, Game Controller support, Vision Pro support, iPhone Duo support

**In-app purchases:** none


### Zero21 Card Game

[App page](https://appshunter.io/ios/app/zero21-card-game/id1550265606)

This number puzzle game challenges you to keep your score between 0 and 21 by collecting cards. Utilize power-up cards and strategic choices to navigate diverse levels and daily challenges. It's a fun, relaxing way to train your brain.

**Highlights:** Keep score between 0 and 21, Collect number cards, Use power-up cards, Unlock new card collections, Daily challenges, Diverse card layouts

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is What the Shell free?

What the Shell is free to download, with no in-app purchases.

### Is Zero21 Card Game free?

Zero21 Card Game is free to download, with no in-app purchases.

### Which has better reviews, What the Shell or Zero21 Card Game?

What the Shell is rated higher. What the Shell averages 5.0 out of 5 from 6 ratings, while Zero21 Card Game averages 4.0 from 3 ratings.

### Do What the Shell or Zero21 Card Game have ads?

Zero21 Card Game shows ads; What the Shell does not.

### Which is updated more often, What the Shell or Zero21 Card Game?

What the Shell ships an update every 8 days, and Zero21 Card Game every 65 months. Most recently, What the Shell was updated on November 1, 2026 and Zero21 Card Game on November 3, 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.*