Fruit Box Open Source

English | 日本語 | 한국어

Play online in English

The open-source, framework-free edition of Fruit Box. It uses plain HTML, CSS, and JavaScript and keeps the same board generator and game rules as the online game.

Run it

Open index.html directly, or serve this directory with any static server:

python -m http.server 8080

Then open http://localhost:8080.

The game itself has no build step and no runtime dependency. The Google Fonts request is optional; the page falls back to local fonts when offline.

Test the engine

The deterministic engine has a zero-dependency Node test:

node tests/engine.test.mjs

It verifies 50 seeds, deterministic output, valid solution steps, complete board clearing, and strict selection boundaries.

Files

File	Purpose
index.html	Minimal English game page
styles.css	Board, controls, responsive layout, and fade-in motion
app.js	DOM rendering, pointer/keyboard input, timer, hints, sound, and local best score
engine.js	Pure browser game engine exposed as window.FruitBoxEngine
tests/engine.test.mjs	No-dependency engine verification
docs/PLAY_GUIDE.md	Illustrated gameplay guide (also available in Japanese and Korean)
docs/ALGORITHM.md	Algorithm notes (also available in Japanese and Korean)
assets/	Gameplay screenshot, architecture image, and solvable-board flow image

Rules

• The board is always 17 × 10 (170 apples).
• Each round lasts 120 seconds.
• A rectangle selects the active apples whose centers are strictly inside it.
• The selected values must add up to exactly 10 to clear.
• Score is the number of apples cleared.
• The daily board is deterministic and changes at UTC 05:00.
• Resetting during the same day restores the same board and clears progress.

Gameplay guide

Read the illustrated gameplay guide for controls, selection rules, hints, timing, and the Korean reference article.

How solvability works

The generator creates a complete solution before it creates the visible board:

flowchart LR
  A[Daily seed] --> B[Seeded random source]
  B --> C[Choose weighted groups]
  C --> D[Split each group to sum 10]
  D --> E[Find rectangle placements]
  E --> F{Placement succeeds?}
  F -- No --> C
  F -- Yes --> G[Return board + solution]
  G --> H[Player selection]
  H --> I{Sum equals 10?}
  I -- No --> H
  I -- Yes --> J[Clear and score]

See docs/ALGORITHM.md for the data model, weighted group distribution, prefix-sum placement, timing model, and complexity notes.

Keeping parity with the online game

engine.js is a browser-global port of the pure functions in the online lib/fruit-box-engine.ts. It keeps the same:

1. LCG seeded random source and UTC 05:00 daily seed.
2. Weighted 2–10 cell groups.
3. Random integer partitions whose sum is 10.
4. Prefix-sum rectangle candidates and certified solution steps.
5. Strict center-point selection, clearing, hint fallback, and time formatting.

The static app.js only replaces the React state orchestration. The game remains client-side and deterministic, so this edition is intended for learning, forks, and static hosting rather than server-verified competitions.

Related links

• Fruit Box online
• フルーツボックス オンライン
• 사과게임 온라인
• 사과 게임 가이드
• Fruit Box: A Practical Analysis of the Sum-10 Puzzle
• Open-source repository

License

MIT