Case Study: Prelude of the Chambered Reborn

To conclude this series, what better than a concrete case study? Here’s how I used Claude Code to recreate Prelude of the Chambered, Notch’s game (Minecraft creator), with a modern stack.

To discover the project in detail, read my dedicated article: Prelude of the Chambered Reborn: Renaissance of a Notch classic

Also see my other retro game project in TypeScript: GBTS - A GameBoy Emulator

The Project

Context

Prelude of the Chambered is a dungeon crawler created by Notch in 48h during a game jam in 2011. The original code is in Java, with a homemade raycasting rendering engine.

Objective

Recreate the game with:

• TypeScript
• Three.js for 3D rendering
• Modern architecture (ES6 modules)
• Automated tests
• Complete documentation

Phase 1: Exploration (Days 1-2)

Analyzing the original code

claude

> @java-src/**/*.java Analyze the original game architecture.
> Identify the main components and their responsibilities.

Claude identified:

• Art.java: Texture and sprite management
• Game.java: Main game loop
• Level.java: Level structure
• Entity.java: Entity system (player, enemies)
• Screen.java: Raycasting rendering

Planning the migration

> ultrathink. Propose a modern TypeScript architecture
> to recreate this game with Three.js

Claude proposed:

src/
├── core/
│   ├── Game.ts         # Game loop
│   ├── Renderer.ts     # Three.js wrapper
│   └── Input.ts        # Controls management
├── world/
│   ├── Level.ts        # Level structure
│   ├── Tile.ts         # Tile types
│   └── Loader.ts       # Level loading
├── entities/
│   ├── Entity.ts       # Base class
│   ├── Player.ts       # Player
│   └── enemies/        # Different enemies
├── graphics/
│   ├── TextureManager.ts
│   └── SpriteSheet.ts
└── utils/
    └── Math.ts

Phase 2: Setup (Day 3)

Initialize the project

> Initialize a TypeScript project with Vite, Three.js,
> and configure ESLint + Prettier according to conventions.

Claude created:

• package.json with dependencies
• tsconfig.json configured for strict mode
• vite.config.ts with necessary plugins
• .eslintrc.js and .prettierrc

Project CLAUDE.md

> Create a CLAUDE.md that documents the architecture and conventions.

# CLAUDE.md - Prelude Reborn

## Architecture
This project is a remake of Prelude of the Chambered with Three.js.

## Conventions
- Strict TypeScript
- ES6 modules components
- Tests with Vitest
- Naming: PascalCase classes, camelCase functions

## Key files
- src/core/Game.ts: Main entry point
- src/world/Level.ts: Level management
- src/entities/Player.ts: Player logic

Phase 3: Core Engine (Days 4-7)

Rendering system

> Implement the Renderer.ts that wraps Three.js
> to display a first-person dungeon crawler style scene.

Claude created:

• Perspective camera with FPS controls
• Grid system for walls
• Texture management with Three.js TextureLoader

Game loop

> Implement the game loop with:
> - Update at 60 FPS
> - Delta time for physics
> - States (menu, playing, paused)

Level loading

> Analyze @java-src/Level.java and @java-src/Art.java
> to understand the level format.
> Then implement compatible Level.ts.

Claude:

1. Analyzed the original bitmap level format
2. Created a parser for PNG files
3. Implemented 3D geometry generation

Phase 4: Gameplay (Days 8-12)

Entity system

> Implement the entity system inspired by @java-src/Entity.java
> with:
> - Entity base class
> - Collision detection
> - Update/Render cycle

Player and controls

> Implement Player.ts with:
> - WASD movement
> - Mouse rotation
> - E interaction
> - Health and damage

Enemies

> Analyze enemies in @java-src/entities/
> and implement them progressively.
> Start with the simplest one.

Claude proceeded methodically:

1. Bat: Random movement
2. Ghost: Player pursuit
3. Ogre: Patrol + attack
4. Boss: Pattern combination

Combat

> Implement the combat system:
> - Player attack (left click)
> - Damage to enemies
> - Damage to player
> - Visual effects (red flash)

Phase 5: Polish (Days 13-16)

Audio

> Add the audio system with Web Audio API:
> - Background music
> - Sound effects
> - Volume control

UI

> Implement the user interface:
> - Health bar
> - Inventory
> - On-screen messages
> - Pause menu

Optimization

> Profile the rendering and optimize:
> - Frustum culling
> - LOD for distant entities
> - Texture atlasing

Phase 6: Testing and deployment (Days 17-20)

Automated tests

> Generate Vitest tests for:
> - Level loading
> - Collision detection
> - Entity behavior
> - Game state management

Claude generated tests covering:

• Correct level loading
• Wall collision detection
• Enemy behavior
• Game state transitions

CI/CD

> Configure GitHub Actions for:
> - Lint + Type check
> - Tests
> - Build
> - Deploy to GitHub Pages

Documentation

> Generate project documentation:
> - Complete README
> - JSDoc for main classes
> - Contribution guide

Results

Project metrics

What Claude did automatically

• ✅ Analysis of original Java code
• ✅ Architecture proposal
• ✅ Project scaffolding
• ✅ Core systems implementation
• ✅ Java → TypeScript algorithm conversion
• ✅ Test generation
• ✅ CI/CD configuration
• ✅ Documentation

What I did manually

• 🎨 Artistic choices (colors, textures)
• 🔧 Gameplay fine-tuning (speed, damage)
• 🐛 Debugging certain edge cases
• ✍️ Code review and validation

Lessons Learned

What worked well

1. Detailed CLAUDE.md: The richer the context, the better the responses
2. EPCT Workflow: Explore → Plan → Code → Test for each feature
3. Precise @ references: @java-src/Entity.java rather than “the Entity file”
4. ultrathink for design: Solid architecture from the start

What needed adjustments

1. Three.js specific: Claude knows Three.js but not all subtleties
2. Performance: First implementations weren’t optimized
3. Edge cases: Edge cases required specific prompts

Tips for your projects

1. Start with context: A good CLAUDE.md makes all the difference
2. Iterate in small steps: Feature by feature, not all at once
3. Use ultrathink: For design and complex problems
4. Test often: Claude can generate tests, use them
5. Commit regularly: Git checkpoints are your safety net

Series Conclusion

In 20 days, we covered:

1. Installation and first steps
2. Secret syntax #@/!
3. EPCT Workflow
4. Prompt engineering
5. Context management
6. Git workflows
7. Permissions and security
8. Custom slash commands
9. Subagents
10. Skills
11. Plugins and marketplace
12. Hooks
13. MCP
14. IDE integration
15. CI/CD headless
16. Billing and costs
17. Troubleshooting
18. Status line and terminal
19. Tool comparison
20. This case study

Claude Code is a powerful tool that, when used well, transforms how we develop. It’s not a developer replacement, but a productivity multiplier.

Now it’s your turn!

Thank you for following this “Master Claude Code in 20 Days” series. Discover the Prelude Reborn project