Godot Code Review

Systematic review patterns for Godot game development projects.

Common Pitfalls & Anti-Patterns

_process() Abuse

# BAD: Using _process for everything
func _process(delta):
    # Movement that could be in _physics_process
    position += velocity * delta
    # Animation updates
    update_animation()

# GOOD: Use the right callback
func _physics_process(delta):
    # Physics-related movement
    position += velocity * delta

func _process(delta):
    # Non-physics updates (UI, animations)
    update_animation()

Hardcoded Paths

# BAD
var sprite = get_node("Character/Sprite2D")

# GOOD
@onready var sprite = $Sprite2D as Sprite2D

Signal Leaks

# BAD: Forgetting to disconnect signals
func _ready():
    EventBus.some_signal.connect(on_some_signal)
    # If this node is freed, the callback still holds a reference

# GOOD: Auto-disconnect when using method references
func _ready():
    EventBus.some_signal.connect(on_some_signal)  # Godot auto-handles method refs

# GOOD: Manual disconnect for lambdas
func _ready():
    var callback = func(): handle_event()
    EventBus.some_signal.connect(callback)

func _exit_tree():
    EventBus.some_signal.disconnect(callback)

Performance Review Checklist

Callback Selection

Memory Management

• All queue_free() calls have corresponding signal disconnections
• No circular references between nodes
• Large resources (textures, audio) unloaded when no longer needed
• Scene instances properly freed after use
• Autoload nodes don't hold unnecessary references

Code Style Guidelines

GDScript Style

• Use 4-space indentation (not tabs)
• Follow GDScript Style Guide
• Use @export for inspector-exposed variables
• Use @onready for node paths
• Type annotations on function parameters and return values
• Use const for compile-time constants

C# Style

• Use PascalCase for class names, camelCase for members
• Use Godot's [Export] attributes for inspector properties
• Implement _ExitTree() for cleanup of event subscriptions
• Prefer structs for small value types to avoid GC pressure

Memory Management Patterns

# Proper node lifecycle
func spawn_enemy():
    var enemy = enemy_scene.instantiate()
    add_child(enemy)
    # Enemy manages its own cleanup via queue_free() on death

func load_level(level_path: String):
    # Unload previous level
    if current_level:
        current_level.queue_free()
        current_level = null

    # Load new level
    var scene = load(level_path)
    current_level = scene.instantiate()
    add_child(current_level)

Godot 4.7 Code Review Notes

• Check for HDR rendering configuration in project settings
• Review AreaLight3D usage for new 4.7 features (modes, intensity profiles)
• Verify VirtualJoystick is used instead of custom implementations on mobile
• Check that tween_await() replaces nested callback patterns where applicable

Quick Review Commands

# Find all _process calls that might be physics-related
grep -rn "_process" --include="*.gd" scripts/

# Find hardcoded get_node calls (should use @onready)
grep -rn "get_node(" --include="*.gd" scripts/

# Find potential signal leaks (connect without disconnect pattern)
grep -rn "\.connect(" --include="*.gd" scripts/

# Find queue_free usage to verify cleanup
grep -rn "queue_free" --include="*.gd" scripts/

MCP Bridge Tools (Optional — Live Editor Integration)

When the MCP bridge is running (Phase 2), these tools enhance code review:

• script_read — Read any script file for review without opening the editor
• script_validate — Run syntax validation with checkDeprecated: true and suggestTweenAwait: true
• file_search — Search across all project files for patterns (e.g., queue_free, signal leaks)
• file_browse — List project directories to verify structure
• class_db_info — Verify methods/properties exist before flagging issues

Note: MCP tools require the Godot editor to be running with the MCP plugin enabled. Skills work independently without the bridge.

References

• GDScript Style Guide
• Performance Optimization Guide
• Memory Management Patterns