Comparison

Rainbow Piece vs Eat Chess

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

Head to head
About

Rainbow Piece

Features
Read full description

Rainbow Piece: Relaxing Circular Jigsaw. Escape the stress of high scores. Enjoy a pure, calm puzzle experience on your wrist. 【How to Play】 - Move: Drag your finger on the screen to move the pieces. - Rotate: Turn the Digital Crown to rotate the selected piece. 【Choose Your Challenge】 - Normal: Relatively easy, as you solve the puzzle by following the rainbow color gradient. - Hard: Solve the puzzle by relying solely on the shape of the pieces. 【Two Sizes Available】 - 13 Pieces: Large pieces and a small number of pieces make for a casual game. - 25 Pieces: Small pieces and a large number of pieces make for a more thorough game. 【Tip】 Long press the screen any time to return to the start screen. Take your time. Find your peace. Complete the rainbow.

About

Eat Chess

This game combines chess mechanics with a merge puzzle on a compact 4x4 board. Strategically move pieces to merge them into higher-level ones, managing board space and building combos. It offers both solo challenges with various time controls and local multiplayer on a single device.

Highlights
  • Chess merge puzzle gameplay
  • Compact 4x4 board
  • Solo play with time controls
  • Local versus multiplayer
  • Castle Swap mechanic
  • Combo multipliers
  • Apple Watch support
Features
Read full description

Royal Merge is a chess merge puzzle played on a compact 4×4 board. Pick one piece, move it by simplified chess rules, and merge it with a matching piece of the same type and level. Pawns become Knights, then Bishops, Rooks, Queens, Kings, and higher-level Pawns. The board fills fast. A quiet setup move can matter as much as the merge it opens. HOW IT PLAYS Select a piece. Legal squares light up. Move to an empty square, merge with a match, or use Castle Swap when a same-level King and Rook line up with a clear path. Every legal move into empty space and every Castle Swap adds a new Pawn. Pawn Spawn adds a Pawn on every second merge. Royal Reserve drops a Level 1 Pawn, Knight, Bishop, or Rook after every five successful actions. Every arrival can help, and every arrival takes space. Back-to-back merges build a combo multiplier. A move into empty space or a Castle Swap breaks the chain, so timing matters. SOLO Play without a clock, add a Player Clock, set an Increment, or cap the run with a Turn Limit. Official Solo runs can count toward local records, Game Center leaderboards, and achievements. Solo also includes Hint. It points out possible moves, costs part of your current score, and never plays the move for you. VERSUS Two players share one board on the same device. Player 1 starts. After each legal action, the turn passes and the board switches to the active player's chosen chess set. Pieces are shared, not owned. The active player scores only when they make a merge. Versus supports per-player clocks, Increment, a shared Game Clock, and Turn Limit. If a timed player clock hits zero, Clock Collapse keeps 20% of that player's score, resets the clock, and leaves that player on turn. The match continues. COSMETIC OPTIONS Start with free chess sets and the Quiet Royal theme, or add optional cosmetic sets, themes, and the Royal Patron badge. Purchases do not change movement, scores, spawns, hints, timers, Castle Swap, leaderboards, or match results. APPLE WATCH Play Solo or Battle from the Watch app with the same 4×4 board, local save and resume, time controls, Solo undo, direct tap controls, optional Digital Crown selection, ten free board presets, and ten free piece styles. Watch play is standalone and does not require an iPhone connection.

Screenshots

Eat Chess4 screens

Verdict

The call

The clearest difference is in-app purchases: Rainbow Piece at none against Eat Chess's 4. Eat Chess's advantage is update cadence (every 5 days vs every 3 months) and iOS requirement (17.0 vs 26.0). On price, ads 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Eat Chess sells 4 one-off in-app purchases. Rainbow Piece asks for nothing beyond the download.

UpkeepUpdate frequency

Rainbow Piece ships an update every 3 months, Eat Chess every 5 days. The most recent releases landed on October 15, 2026 and October 8, 2026 respectively.

Scorecard3 real differences · 7 level
Rainbow Piece versus Eat Chess: the parameters behind the verdict, then further details
ParameterRainbow PieceEat Chess
PriceFreeFree
Rating—5.0 (2 ratings) — better
Positive reviews—100.0% of reviews
Number of ratings—2 — better
Update frequencyEvery 3 monthsEvery 5 days — better
AdsNoNo
In-app purchasesNo — betterYes
Monetization—Free with in-app purchases
DevicesiPhone, Apple WatchiPhone, iPad, Apple Watch — better
Requires iOS26.017.0 — better
Further details — not scored
Size1 MB49 MB
Age rating4+4+
DeveloperKiyoshi IzumiDavid Lew

In-app purchases

None

Rainbow Piece

No in-app purchases

4 purchases

Eat Chess

One-time4
  • Chess Sets Pack$1.99
  • Themes Pack$1.99
  • Royal Bundle$2.99
Show 1 more
  • Royal Patron$9.99

Questions

Is Rainbow Piece free?
Rainbow Piece is free to download, with no in-app purchases.
Is Eat Chess free?
Eat Chess is free to download, with in-app purchases available.
Do Rainbow Piece or Eat Chess have ads?
Neither Rainbow Piece nor Eat Chess shows ads.
Which is updated more often, Rainbow Piece or Eat Chess?
Rainbow Piece ships an update every 3 months, and Eat Chess every 5 days. Most recently, Rainbow Piece was updated on October 15, 2026 and Eat Chess on October 8, 2026.

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