Comparison

Clue Formula vs DuoDom

Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.

Head to head
About

Clue Formula

Engage in a 3D Mahjong puzzle game featuring IQ-test style tiles. Match selectable pairs to clear levels, with increasing difficulty as you progress. Utilize hints and shuffles to aid your gameplay and compete on leaderboards.

Highlights
  • 3D Mahjong puzzle gameplay
  • IQ-test style tiles
  • Layered 3D levels
  • Hint and shuffle options
  • Leaderboard competition
  • VoiceOver accessibility
Features
Read full description

Clue Formula is a 3D Mahjong puzzle with IQ-test style tiles and pattern-matching challenges. Your goal is to complete all levels. In each level, remove all tiles by selecting matching pairs. Not every matching tile can be selected. A tile is selectable only when it is positioned at the end of a row - when there is no neighboring tile on at least one side (left or right) within the same layer. To complete a level, you need to find matching pairs where both tiles are selectable. Each new level becomes more challenging as you advance. A hint can show all selectable matching pairs. A shuffle can rearrange the remaining tiles and help you continue the level. Key Features: 3D Mahjong Puzzle: Match selectable pairs and clear each level. IQ-Test Style Tiles: Match tiles using shapes and symbols. Layered 3D Levels: Look through rows and layers to find selectable matching pairs. Leaderboards: Complete levels and compete for a place on the leaderboards. Accessibility and Device Support: Clue Formula is fully playable with VoiceOver. Clue Formula is fully supported on Mac. Extra hints and extra shuffles are available for purchase.

About

DuoDom

Features
Read full description

DuoDom — the laid-back sliding puzzle in pixel-art retro style. A board fills with stones marked 1 to 6. Slide them across the empty squares so that two matching stones land right next to each other — they vanish as a pair. Clear the whole board to win. HOW TO PLAY • Tap a stone to select it. • Tap an empty neighbouring square to slide the stone there. • When two matching stones meet edge to edge, they disappear. • Clear the entire board — level done. Every puzzle is guaranteed solvable — a built-in solver verifies each level before you see it. No frustration, no dead ends. FEATURES • Hundreds of solver-checked puzzles • Pixel-art graphics in lovingly crafted retro style • Smooth animations at 60 FPS • Per-level highscores — how few moves can you do it in? • Trophy system for special achievements • Built-in tutorial • Pause with settings for volume and language • Synthesized sound effects straight from the game • Works in any screen size, portrait and landscape 20 LANGUAGES DuoDom auto-detects your device language and lets you switch live anytime: Deutsch, English, Français, Español, Italiano, Português, Nederlands, Polski, Čeština, Slovenčina, Magyar, Română, Türkçe, Русский, Українська, Ελληνικά, Svenska, Dansk, 日本語, 中文. Perfect for a coffee break, a train ride, or winding down after work. Slide, combine, win. DuoDom — side by side, gone for good.

Screenshots

Clue Formula4 screens
DuoDom3 screens

Verdict

The call

The clearest difference is in-app purchases: DuoDom at none against Clue Formula's 2. DuoDom also leads on ads (none vs shown). Clue Formula's advantage is update cadence (every 4 days vs monthly). On price, device support and iOS requirement 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Clue Formula sells 2 one-off in-app purchases. DuoDom asks for nothing beyond the download.

UpkeepUpdate frequency

Clue Formula ships an update every 4 days, DuoDom monthly. The most recent releases landed on October 16, 2026 and October 1, 2026 respectively.

Scorecard3 real differences · 7 level
Clue Formula versus DuoDom: the parameters behind the verdict, then further details
ParameterClue FormulaDuoDom
PriceFreeFree
Rating5.0 (4 ratings) — better—
Positive reviews100.0% of reviews—
Number of ratings4 — better—
Update frequencyEvery 4 days — betterMonthly
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, Mac — betteriPhone, iPad
Requires iOS17.017.0
Further details — not scored
Size22 MB1 MB
Age rating4+4+
Developerx2line.com LLCJosef Sejrek

In-app purchases

2 purchases

Clue Formula

One-time2
  • Hint$0.99
  • Shuffle$0.99
None

DuoDom

No in-app purchases

Questions

Is Clue Formula free?
Clue Formula is free to download, with in-app purchases available.
Is DuoDom free?
DuoDom is free to download, with no in-app purchases.
Do Clue Formula or DuoDom have ads?
Clue Formula shows ads; DuoDom does not.
Which is updated more often, Clue Formula or DuoDom?
Clue Formula ships an update every 4 days, and DuoDom monthly. Most recently, Clue Formula was updated on October 16, 2026 and DuoDom on October 1, 2026.

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