Suika Game (Watermelon Game)

A browser-based clone of the Suika Game — a physics-based puzzle game where you drop fruits into a container. When two identical fruits collide, they merge into the next larger fruit. The goal is to create a watermelon and get the highest score.

Built with ClaudeKit.

Tech Stack

Category	Tool	Version	Purpose
Runtime	Matter.js	^0.20.0	2D rigid-body physics engine
Rendering	Canvas2D	(built-in)	Fruit drawing, UI overlay, game-over screen
Build	Vite	^8.0.4	Dev server, ES module bundling, production builds
Testing	Vitest	^4.1.4	Unit and integration tests
Language	JavaScript (ES Modules)	—	Vanilla JS, no framework
Dev Tooling	ClaudeKit	—	Git hooks for linting, type-checking, testing, self-review

Project Structure

src/
  main.js          Entry point: initializes game, attaches event listeners
  game.js          Game class: orchestrates engine, renderer, input, state
  physics.js       Matter.js engine setup, world configuration, walls
  renderer.js      Canvas2D rendering: fruits, walls, UI overlay
  input.js         Mouse/touch input handling, drop control
  fruits.js        Fruit definitions (sizes, colors, labels, progression)
  merger.js        Collision detection callback, merge logic, scoring
  constants.js     Game dimensions, physics tuning, timing constants
  style.css        Page styling
  *.test.js        Vitest test files
index.html         Single HTML page with canvas element
specs/             Feature and bugfix specifications

Getting Started

npm install
npm run dev

Open the URL shown in the terminal (default: http://localhost:5173).

How to Play

1. Move your mouse (or touch on mobile) to position the fruit
2. Click/tap to drop it into the container
3. When two identical fruits touch, they merge into the next larger fruit
4. The fruit chain goes: Cherry → Strawberry → Grapes → Dekopon → Persimmon → Apple → Pear → Peach → Pineapple → Melon → Watermelon
5. Game ends when fruits stack above the danger line

Scripts

Command	Description
npm run dev	Start Vite dev server with HMR
npm run build	Production build to dist/
npm run preview	Preview the production build
npm test	Run all tests once
npm run test:watch	Run tests in watch mode