Using Cursor to Build Games

Step 1: Install Cursor and Open Your Game Project

Download Cursor from cursor.com and install it on your platform. Cursor is available for Windows, macOS, and Linux. Because it is built on VS Code, your existing extensions, themes, and keybindings transfer directly. If you already use VS Code for game development, the transition is seamless.

Open your game project folder in Cursor the same way you would in VS Code. The editor indexes your project files to build context for AI suggestions. For large game projects with thousands of files, the initial indexing takes a moment but only happens once. After indexing, Cursor understands your file structure, import relationships, and type definitions.

Verify that your language-specific extensions are active. For web game development with TypeScript or JavaScript, the built-in language support is sufficient. For Godot (GDScript), Unity (C#), or other engines, install the appropriate language extension from the marketplace. Cursor's AI features work with any language that has syntax support in VS Code.

Step 2: Write a .cursorrules File for Your Engine

The .cursorrules file is the single most important configuration for getting good AI output in a game project. Create it in your project root directory. This plain text file tells Cursor about your engine, architecture, conventions, and constraints. Every AI interaction in the editor reads this file and respects its instructions.

Start with your engine and version. State clearly: "This is a Babylon.js 7 project" or "This project uses Phaser 3.80 with TypeScript." Include your project's major systems and where they live in the file tree. A game project might list: "Rendering code is in src/rendering/, physics in src/physics/, entities in src/entities/, UI in src/ui/, and game state management in src/state/."

Document your coding conventions explicitly. Specify naming patterns (camelCase for functions, PascalCase for classes, UPPER_SNAKE for constants), your preferred module structure (ES modules with named exports), and architectural patterns (entity-component-system, event-driven communication between systems). If you use specific design patterns consistently, name them.

Add constraints that prevent common AI mistakes. For example: "Never modify TransformNode positions directly, always use the MovementSystem.move() method" or "All asset loading must go through AssetManager, never create loaders directly" or "Physics bodies are managed by PhysicsWorld, never apply forces outside the physics update loop." These constraints prevent the AI from generating technically valid code that violates your architecture.

Keep the file focused and concise. The AI reads it before every interaction, so excessive length dilutes the important information. Aim for one to two pages of clear, factual instructions rather than lengthy explanations.

Step 3: Use Tab Completion for Game Code Patterns

Cursor's tab completion goes beyond traditional autocomplete by predicting multi-line code blocks based on your recent edits and project context. As you type, ghost text appears showing what Cursor thinks you want to write next. Press Tab to accept, or keep typing to get a different suggestion.

Tab completion is most effective for repetitive game code patterns. When you are defining entity components and you just finished writing a HealthComponent class, tab completion will suggest a structurally similar class when you start typing the next component. It picks up on your naming conventions, property types, method signatures, and initialization patterns.

For game loop code, tab completion understands update patterns. If your project consistently uses a pattern like checking elapsed time, updating physics, processing input, and rendering, the AI predicts the next block in that sequence based on what you have already written in similar functions.

Event handler registration is another area where tab completion saves significant time. After you write one handler registration like "eventBus.on('playerDamaged', this.handlePlayerDamaged.bind(this))," tab completion suggests similar registrations for related events based on your event naming patterns and existing handler methods.

The quality of tab predictions improves as you work. Cursor learns from your edits within the current session, so the more code you write, the better it predicts your patterns. This session-level learning is particularly valuable during focused coding sessions where you are building out a single system.

Step 4: Edit Game Logic with Cmd+K Inline Editing

Cmd+K (Ctrl+K on Windows and Linux) opens Cursor's inline editing mode. Select a block of code, press the shortcut, and type a natural language instruction describing how to change the selected code. Cursor rewrites the selection in place based on your instruction.

This mode excels at gameplay mechanic iterations. Select a movement function and type "add acceleration and deceleration with 0.3 second ramp-up time" to transform a simple velocity assignment into smooth interpolated movement. Select a collision handler and type "add knockback force proportional to impact velocity" to extend the behavior without restructuring the function.

Inline editing is also effective for converting between patterns. Select a callback-based async function and type "convert to async/await" to modernize the control flow. Select a switch statement for game state transitions and type "convert to a state machine pattern with enter and exit methods" to restructure the logic.

For shader code, select a basic material setup and type "add fresnel rim lighting with a blue tint" to extend the visual effect. While complex shader work still requires manual expertise, Cmd+K handles common modifications to existing shaders reliably.

When iterating on game feel, inline editing lets you make rapid adjustments. Select the physics parameters section and type "increase jump height by 30% and add a brief hang time at the apex" to fine-tune character movement without manually calculating new values. The AI understands game design terminology and translates it into parameter changes.

Step 5: Build Multi-File Features with Composer

Composer is Cursor's multi-file editing mode, designed for features that span several files in your project. Open it from the command palette or the dedicated shortcut. Describe the feature you want to add, and Composer reads relevant files, plans the implementation, and generates coordinated edits.

For game development, Composer handles the kind of cross-cutting features that are tedious to implement manually. Telling Composer "add an inventory system with a 6x4 grid, item stacking up to 99, and drag-and-drop reordering" generates the data model, the UI component, the input handling for drag interactions, and the serialization logic across multiple files.

Composer works best when you have clear architectural boundaries. If your project follows entity-component-system patterns with well-separated concerns, Composer can add a new component type by editing the component definition file, updating the component registry, adding rendering logic for the new component, and creating factory functions. The cleaner your architecture, the better Composer's multi-file edits.

Review Composer's generated edits carefully before applying them. The preview shows every file that will be modified and the exact changes. For game code where a wrong edit can break physics, rendering, or game state, reviewing each change is essential. Accept edits file by file if you want to apply some but not others.

Complex features benefit from breaking the Composer prompt into phases. Rather than asking for a complete multiplayer lobby system in one prompt, ask first for the data model and state management, apply those changes, then ask for the UI layer, then the network synchronization. Each phase builds on real, reviewed code.

Step 6: Reference Engine Docs with @docs

Cursor supports @docs references that let you point the AI at external documentation. This is particularly valuable for game development because engine APIs change between versions, and the AI's training data may not cover the exact version you are using.

Add your engine's documentation URL as a @docs source in Cursor's settings. For Babylon.js, point it at the official API documentation. For Phaser, add the Phaser 3 API docs. For Three.js, add the Three.js documentation site. When Cursor generates code, it consults these docs for accurate API usage.

You can reference docs directly in prompts with @docs. Type "@docs BabylonJS" in a Composer prompt or Cmd+K instruction to explicitly tell the AI to check the documentation for that specific generation. This is useful when you know the AI might use outdated API calls for a feature that changed in a recent engine version.

For custom or internal libraries that your game depends on, you can add local documentation files as @docs sources. If your team maintains an internal framework with its own API reference, pointing Cursor at those docs ensures the AI generates code that correctly uses your internal APIs.

Step 7: Iterate and Refine Generated Game Code

AI-generated game code almost always needs refinement. The AI produces structurally correct code that compiles and runs, but gameplay feel, performance characteristics, and edge case handling require human judgment and playtesting.

Run the generated code in your game and observe the behavior. If the AI generated a movement system, test the feel at different frame rates and with different input devices. If it generated a particle effect, check that it looks right at various camera distances. If it generated a state machine, test all transitions including interrupted and concurrent states.

Use Cmd+K for targeted refinements rather than regenerating from scratch. "The dash feels too floaty, reduce the air control during dash and increase ground friction on landing" is a better prompt than re-describing the entire dash mechanic. Iterative refinement preserves the parts that work while adjusting the parts that need tuning.

Pay attention to performance. AI-generated code is optimized for correctness and readability, not necessarily for runtime performance. Check that generated code does not allocate objects inside update loops, does not perform unnecessary calculations every frame, and uses appropriate data structures for the access patterns your game requires. Profile if the generated code is in a hot path.