add-feature
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.jsonto identify the engine (Three.js or Phaser) - Read
src/core/Constants.jsfor existing configuration - Read
src/core/EventBus.jsfor existing events - Read
src/core/GameState.jsfor 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:
- What it does: Describe the feature from the player's perspective
- How it works: List the new files, events, and settings that will be created
- 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:
- Create the new module in the correct
src/subdirectory - Add ALL new events to
EventBus.jsEvents enum - Add ALL configuration values to
Constants.js(zero hardcoded values) - Add any new state domains to
GameState.js - Wire the new system into
Game.js(import, instantiate, update in loop) - Use EventBus for ALL communication with other systems
- Follow the existing code style and patterns in the project
Step 4: Verify
- Run
npm run buildto 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:
- What the feature does (from the player's perspective)
- What files were created or changed
- How to test it — "Run
npm run devand try [specific action]"
Example Usage
Adding a power-up
/add-feature add a speed boost power-up that spawns randomly
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
/add-feature add combo multiplier that increases when you score quickly
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-gameto polish the visuals,/game-creator:add-audiofor music and sound effects, or/game-creator:review-gamefor a full quality check.