Memory Game / 神経衰弱

A memory card matching game built with vanilla JavaScript — zero dependencies, no build step.

Live demo: https://sen.ltd/portfolio/memory-game/

Features

• 4 difficulty levels: Easy (4×3), Medium (4×4), Hard (6×6), Expert (8×8)
• 5 card themes: Emoji, Numbers, Alphabet, Shapes, Japanese Hiragana
• Smooth CSS 3D flip animation
• Moves counter & timer
• Best time / best moves saved in localStorage (per difficulty + theme)
• Confetti animation on win
• Dark / Light theme toggle
• Japanese / English UI
• Mobile-friendly responsive layout
• Keyboard accessible (Tab + Enter/Space)

Quick Start

npm run serve
# → http://localhost:8080

No installation needed. Open index.html directly in a browser for offline play.

Tests

npm test

Uses Node.js built-in test runner (node:test). No extra dependencies.

Project Structure

memory-game/
├── index.html        # Single-page app shell
├── style.css         # All styles (CSS custom properties for theming)
├── src/
│   ├── main.js       # DOM wiring, rendering, event handling
│   ├── memory.js     # Pure game logic (immutable state)
│   └── i18n.js       # ja/en translations + difficulty config
├── tests/
│   └── memory.test.js
├── assets/
└── package.json

How to Play

1. Choose a difficulty and theme
2. Click cards to reveal them
3. Match all pairs as quickly and efficiently as possible
4. Beat your best time!

License

MIT © 2026 SEN LLC (SEN 合同会社)

Links

• 🌐 Demo: https://sen.ltd/portfolio/memory-game/
• 📝 dev.to: https://dev.to/sendotltd/a-memory-card-matching-game-with-css-3d-flip-and-immutable-state-3g8n