Add a new gameplay feature to an existing browser game following its architecture patterns. Use when the user says "add a feature", "add double-jump", "add a power-up", "add a leaderboard", or describes a specific game mechanic to implement. Do NOT use for visual-only changes (use design-game) or re

Performance Notes Take your time to do this thoroughly Quality is more important than speed Do not skip validation steps Add Feature Add a new feature to your game. Just describe what you want in plain English — for example, "add a double jump power up" or "add a high score leaderboard" — and the feature will be built following your game's existing patterns. Instructions The user wants to add: $ARGUMENTS Step 1: Understand the codebase Read package.json to identify the engine (Three.js or Phaser) Read src/core/Constants.js for existing configuration Read src/core/EventBus.js for existing events Read src/core/GameState.js for existing state Read src/core/Game.js (or GameConfig.js) for existing system wiring Read existing scene and gameplay files to understand what's already built Step 2: Plan the feature Before writing code, explain the plan in plain English: 1. What it does : Describe the feature from the player's perspective 2. How it works : List the new files, events, and settings that will be created 3. What it touches : List existing files that need small changes to wire in the feature Then determine what's needed technically: New module file(s) and where they go in the directory structure New events to add to the Events enum New constants to add to Constants.js New state to add to GameState.js How to wire it into the Game orchestrator Step 3: Implement Follow these rules strictly: 1. Create the new module in the correct src/ subdirectory 2. Add ALL new events to EventBus.js Events enum 3. Add ALL configuration values to Constants.js (zero hardcoded values) 4. Add any new state domains to GameState.js 5. Wire the new system into Game.js (import, instantiate, update in loop) 6. Use EventBus for ALL communication with other systems 7. Follow the existing code style and patterns in the project Step 4: Verify Run npm run build to confirm no errors Confirm the feature integrates without breaking existing systems Check that no circular dependencies were introduced Ensure event listeners are properly cleaned up if applicable Summarize what was added in plain English Troubleshooting Game breaks after adding feature Cause: New code conflicts with existing EventBus events or GameState fields. Fix: Check for event name collisions in EventBus.js. Ensure new state fields have defaults in GameState.reset(). Feature works but breaks existing gameplay Cause: Modified shared constants or collision groups. Fix: Add new constants rather than changing existing ones. Test original gameplay after changes. Output Tell the user: 1. What the feature does (from the player's perspective) 2. What files were created or changed 3. How to test it — "Run npm run dev and try [specific action]" Example Usage Adding a power up Result: Creates src/entities/PowerUp.js , adds POWER UP events to EventBus, adds spawn timing and duration to Constants.js, wires into Game.js. Player collects power up → speed doubles for 8 seconds. Adding a scoring mechanic Result: Adds comboMultiplier and comboTimer to GameState, creates combo logic in scoring system, adds COMBO CHANGED event for UI updates. Tips You can run this command as many times as you want to keep adding features. Each one builds on the last. When you're happy with the gameplay, run /game creator:design game to polish the visuals, /game creator:add audio for music and sound effects, or /game creator:review game for a full quality check.

add-feature