Goldoku - Deluxe Sudoku

Goldoku - Deluxe Sudoku is a premium HTML5 Sudoku game with a Japanese lacquer and gold visual style, built with Phaser 3. Every 9x9 puzzle is procedurally generated with a verified unique solution, and the four difficulty bands are tuned so Hard and Expert genuinely require advanced solving logic, not just naked singles.

100% client-side. No backend, no database, no paid assets, no build step: unzip, serve the folder, play.

Highlights

• Procedurally generated 9x9 puzzles with verified unique solutions
• Four difficulty bands: Easy, Medium, Hard, Expert (Hard and Expert guaranteed to require advanced logic)
• Daily Challenge: a deterministic seeded puzzle, identical for every player on the same calendar day, with streak tracking
• Pencil (candidate) notes with automatic candidate removal from peers when a number is placed
• Digit counters on the number pad that dim digits placed 9 times
• Erase, unlimited undo and redo history
• 3 hints per puzzle with a golden ring pulse animation
• Mistake limit (3) with game over and same-puzzle retry flow
• Row, column and box highlighting plus matching-digit highlighting
• Timer, pause overlay (auto-pauses when the tab is hidden), autosave and Continue
• Victory screen with new-best-time detection and gold particle celebration
• Per-difficulty and global statistics: games, wins, best time, average time, win streaks
• Synthesized sound effects and ambient music with separate toggles (Web Audio, zero audio files)
• How To Play tutorial carousel (4 slides)
• Keyboard support: arrows to move, 1-9 to place, N notes, H hint, Z undo, Y redo, Escape pause
• localStorage persistence and responsive portrait-first FIT scaling for any screen size

Technology

• Phaser 3.80 (loaded from CDN, or bundle it locally for full offline: instructions included)
• Vanilla JavaScript ES modules, no framework, no transpiler, no build step
• Web Audio API for all sound and music (synthesized at runtime)
• localStorage persistence, no server
• Single reskin and rebalance file: src/config.js

Engine Tests

The sudoku engine ships with unit tests (node tests/sudoku.test.mjs) that verify solution validity, puzzle uniqueness, clue counts per difficulty band, advanced-logic requirements for Hard and Expert, and daily challenge determinism.

What You Get

• Full readable ES-module source code: scenes, systems, sudoku engine and UI modules
• Unit tests for the sudoku engine (solver, uniqueness, difficulty bands, daily seed)
• documentation.html with embedded screenshots: setup, rebranding, reskinning and tuning guide

Please note: this is a source code template. Basic knowledge of HTML/JavaScript and running a local static server is required to customize it. Every puzzle is generated at runtime, so there is no fixed puzzle content to configure. If you have questions, use the contact form on the site, I usually reply within 24 hours.