cirnogodot/Scripts/MainMenu.cs

using Godot;
using System;

public partial class MainMenu : Control
{

	[Export]
	public string GameScene { get; set; }

	[Export]
	public string MainMenuScene { get; set; }

	// Called when the node enters the scene tree for the first time.
	public override void _Ready()
	{
	}

	// Called every frame. 'delta' is the elapsed time since the previous frame.
	public override void _Process(double delta)
	{
	}

	private void _on_start_button_pressed()
	{
		if (GameScene != null) {
			GetTree().ChangeSceneToFile(GameScene);
		}
	}

	private void _on_debug_button_pressed()
	{

	}

	private void _on_mainmenu_button_pressed()
	{
		if (MainMenuScene != null) {
			GetTree().ChangeSceneToFile(MainMenuScene);
		}
	}

	private void _on_exit_button_pressed()
	{
		GetTree().Quit();
	}
}