What the Shell vs Zero21 Card Game
Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.
What the Shell
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.
- Simultaneous secret moves
- Piece capture mechanics
- Egg hatching and capture
- Local and online multiplayer
- Offline AI opponent
- Controller support
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You both move at the same time, in secret. Only when the turtles land do you find out whose plan just fell apart. Oh no — this ain't your traditional five-in-a-row. What the Shell is the one you reach for when you and a friend are bored on the couch: "Wanna play What the Shell?" A game between two beginners can be over in three minutes, and somehow you're still at it two hours later, laughing every time your minds collide and another egg turns up on the board. "Simultaneous play boosts the fun of this intuitive, yet surprisingly deep board game." — Matthias Titze, Clarc producer (German Computer Game Award winner) There's no taking turns, and nobody goes first — so nobody gets the first-player edge. You lock in your move, your friend locks in theirs, and the board resolves both at once. Strategy still wins games, but you're up against a mind you can't see, and you never know where she just played. Sandwich two of their turtles and they're gone. Both reach for the same square and your turtles crash into an egg — and an egg is a curious thing: you can capture it, or hatch it. One bold move flips a game you'd already written off. Capture at the right moment and a chain reaction can tear through the position your friend spent the whole game building. It's never won or lost until the last move. Made for two: • Sit down together, each on your own phone or tablet, and battle it out face to face — best enjoyed in the same room • Or play online at your own pace, whether your friend's across town or across the world • No one around? Tap Quick Match for a random opponent, or take on the panda offline, from an easygoing Newcomer to a tough Expert • Got a controller? Connect it to your iPad or iPhone and play however you want Read the board, then read your friend. Capture a couple of turtles, deal with the eggs, line up five in a row — and enjoy the look on his face when it all comes together.
Zero21 Card Game
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.
- Keep score between 0 and 21
- Collect number cards
- Use power-up cards
- Unlock new card collections
- Daily challenges
- Diverse card layouts
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"ZERO21 CARD GAME Zero21 Card Game is a number games with solitaire card. It is fun, relax but helps to train your brain. ***HOW TO PLAY*** The game rule is simple: Try to stay between 0 and 21. - Collect the number card on the board - Choose the right one to keep the sum lower than 21 and greater than 0 - Use the power up cards to help you solve this math game ***FEATURES*** - PICK YOUR STYLE: Many unique stylish card collections for your choice to play to keep things fresh everyday. - AMAZE IN EVERY LEVEL: Diversity card layouts at each level let the game more interesting. - FINISH DAILY CHALLENGE to unlock new card collections. - Golden card keeps your current number at the golden one. - See the next number with forseen card. - Hold button help to keep the card for the next move. - Remove the unused card with Delete button. You should not miss this mathgame because it is TOTALLY FREE and help you BE SMARTER everyday!
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | What the Shell | Zero21 Card Game |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (6 ratings) — better | 4.0 (3 ratings) |
| Positive reviews | 100.0% of reviews — better | 0.0% of reviews |
| Number of ratings | 6 — better | 3 |
| Update frequency | Every 8 days — better | Every 65 months |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free — better | Ad-supported |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 16.0 | 15.6 — better |
| Further details — not scored | ||
| Size | 138 MB | 58 MB |
| Age rating | 4+ | 4+ |
| Developer | Chuck Smith | Le Nhung |
Customer experience
What the Shell
Zero21 Card Game
In-app purchases
What the Shell
No in-app purchases
Zero21 Card Game
No in-app purchases
Questions
Is What the Shell free?
Is Zero21 Card Game free?
Which has better reviews, What the Shell or Zero21 Card Game?
Do What the Shell or Zero21 Card Game have ads?
Which is updated more often, What the Shell or Zero21 Card Game?
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