💣Boomerboy

Retro Pixel Multiplayer Arena
A local multiplayer game for 2–4 players on a shared keyboard. Pure HTML5 Canvas — one file, zero dependencies.
_{Built with Kiro
🇩🇪 Deutsche Version}

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Table of Contents

• Features
• Quick Start
• Controls
• How to Play
• Architecture
• Development
• Tests
• Built with Kiro
• License

Features

• 🎮 2–4 players on a single keyboard (local multiplayer)
• 💣 Bombs, chain explosions and destructible walls
• ⚡ Power-ups (extra bombs, bigger range, speed boost)
• 🎨 Pixel-art retro graphics with HTML5 Canvas
• 📦 Zero dependencies — a single HTML file
• 🔄 Randomly generated maps for every round
• 🌐 Bilingual — German and English UI (auto-detected, switchable)

Note: The game auto-detects browser language (DE/EN). A toggle button is available on the start screen.

Quick Start

# Option 1: Just open the file
open index.html

# Option 2: Clone and open
git clone https://github.com/achimbarczok/boomerboy.git
cd boomerboy
open index.html

No server, no build, no installation. Works in any modern browser.

Controls

Player	Move	Bomb
🔴 Player 1	W A S D	Space
🟡 Player 2	↑ ← ↓ →	Enter
🟢 Player 3	I J K L	U
🔵 Player 4	Num8 Num4 Num5 Num6	Num0

Note: Player 4 requires NumLock to be enabled.

How to Play

1. Select player count on the start screen (2, 3, or 4)
2. Place bombs to destroy walls and eliminate opponents
3. Collect power-ups hidden under destructible walls:

Power-Up	Symbol	Effect
Extra Bomb	B (purple)	+1 bomb capacity
Bigger Explosion	E (orange)	+1 explosion range
Speed	S (cyan)	+0.3 movement speed

4. Last player standing wins the round
5. Simultaneous elimination of all remaining players → draw

Architecture

Component	Technology
Rendering	HTML5 Canvas (pixel-art, imageSmoothingEnabled: false)
Game logic	Vanilla JavaScript (ES Modules)
Game loop	requestAnimationFrame with delta-time
Testing	Vitest + fast-check (property-based)
Architecture	Single-file (inline) + modular test version

Project Structure

├── index.html              # Complete game (playable without build)
├── src/
│   └── game.js             # Game logic as ES module (for tests)
├── tests/
│   ├── board.test.js       # Board generation tests
│   ├── bomb.test.js        # Bomb & explosion tests
│   ├── player.test.js      # Player movement tests
│   ├── powerup.test.js     # Power-up tests
│   ├── input.test.js       # Input handling tests
│   ├── gamestate.test.js   # Game state tests
│   └── generators.js       # Shared fast-check generators
├── screenshot/
│   └── gameplay.png
├── package.json
└── vitest.config.js

Development

npm install              # Install dev dependencies
npm test                 # Run all tests
npm run test:watch       # Watch mode

Tests

165 tests including 18 property-based tests validating universal correctness properties.

npm test

 ✓ tests/board.test.js (20)
 ✓ tests/bomb.test.js (28)
 ✓ tests/gamestate.test.js (22)
 ✓ tests/input.test.js (40)
 ✓ tests/player.test.js (31)
 ✓ tests/powerup.test.js (15)
 ✓ tests/setup.test.js (9)

 Test Files  7 passed (7)
      Tests  165 passed (165)

Property-based tests verify:

• Board structure invariants (dimensions, borders, grid pattern)
• Start zone placement for 2/3/4 players
• Movement exactly one cell per step
• Collision blocking (walls, bombs)
• Explosion calculation with wall blocking
• Chain explosion propagation
• Player elimination on explosion cells
• Power-up spawn validity and effect application
• Simultaneous input independence
• Win condition correctness

Built with Kiro

This project was developed using Kiro, an AI-powered IDE. Development followed the Spec-Driven Development methodology:

1. Requirements as user stories with acceptance criteria
2. Technical design with correctness properties
3. Implementation plan with referenced requirements
4. Property-based tests (fast-check) for verification

Spec documents are in .kiro/specs/.

License

MIT