
Add Feature
- 519 installs
- 305 repo stars
- Updated May 25, 2026
- opusgamelabs/game-creator
add-feature is an agent skill that lets an AI coding agent reliably add new mechanics, levels, or systems to an existing browser game project for developers who extend OpusGameLabs game-creator architectures without brea
About
add-feature is an OpusGameLabs game-creator agent skill (version 1.3.0, MIT license) for adding gameplay features to existing browser games. The skill follows the project's architecture patterns when implementing mechanics such as double-jump, power-ups, or leaderboards, and runs validation steps rather than skipping them. Developers reach for it when extending game logic after the base game exists. Use design-game for visual-only changes and add-assets for replacing shapes with sprites instead.
- Agent skill that adds complete, working features to game codebases
- Follows structured implementation workflow with clear handoffs
- Produces playable, integrated game features instead of fragmented code
- Works with Claude Code, Cursor, and similar game-creator agents
- Reduces context loss when expanding game scope incrementally
Add Feature by the numbers
- 519 all-time installs (skills.sh)
- +15 installs in the week ending Aug 4, 2026 (Skillselion tracking)
- Ranked #47 of 247 Game Development skills by installs in the Skillselion catalog
- Data as of Aug 4, 2026 (Skillselion catalog sync)
npx skills add https://github.com/opusgamelabs/game-creator --skill add-featureAdd your badge
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| Installs | 519 |
|---|---|
| repo stars | ★ 305 |
| Last updated | May 25, 2026 |
| Repository | opusgamelabs/game-creator ↗ |
How do you add a gameplay feature to a browser game?
Let an AI coding agent reliably add new mechanics, levels, or systems to an existing game project.
Who is it for?
Developers extending an existing OpusGameLabs browser game who need architecture-compliant mechanics with validation steps.
Skip if: Developers making visual-only design changes or sprite swaps—use design-game or add-assets instead.
When should I use this skill?
A developer says add a feature, describes a game mechanic like double-jump or power-up, or requests a leaderboard in an existing browser game.
What you get
New gameplay mechanic code, level or system modules, and validated feature integration matching the game's architecture.
- gameplay mechanic module
- validated feature integration
By the numbers
- Skill version 1.3.0
- MIT license
Files
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:
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 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: 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
/add-feature add a speed boost power-up that spawns randomlyResult: 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 quicklyResult: 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.
Related skills
How it compares
Pick this over design-game when the change adds gameplay logic or systems, not purely visual styling.
FAQ
What types of features does add-feature implement?
add-feature implements gameplay mechanics such as double-jump, power-ups, leaderboards, and other systems in existing browser games, following the game-creator architecture and completing validation steps.
When should I use add-feature vs design-game?
Use add-feature for new gameplay mechanics and systems. Use design-game for visual-only changes and add-assets when replacing shapes with sprites in an OpusGameLabs browser game.