Coin.cs

using Godot;
using System;

public partial class Coin : Node2D
{
	public override void _Ready(){}

	public override void _Process(double delta){}
	private CharacterBody2D FindCharacterNode(Node node)
	{
		if (node is CharacterBody2D)
		{
			return (CharacterBody2D)node;
		}

		foreach (Node child in node.GetChildren())
		{
			CharacterBody2D result = FindCharacterNode(child);
			if (result != null)
			{
				return result;
			}
		}

		return null;
	}

	private AudioStreamPlayer2D FindStreamNode(Node node, string name)
	{
		if (node is AudioStreamPlayer2D && node.Name == name)
		{
			return (AudioStreamPlayer2D)node;
		}

		foreach (Node child in node.GetChildren())
		{
			AudioStreamPlayer2D result = FindStreamNode(child, name);
			if (result != null)
			{
				return result;
			}
		}

		return null;
	}

	private void _on_area_2d_body_entered(Node body)
	{
		Node exampleLevel = GetTree().Root;

		CharacterBody2D character = FindCharacterNode(exampleLevel);
		AudioStreamPlayer2D coinSound = FindStreamNode(exampleLevel, "PickUp");

		if (character != null && body == character)
		{
			if(coinSound == null)
			{
				GD.Print("Coin sound not found");
				return;
			}

			coinSound.Play();

			DataCoin.CoinGlobal.CoinCount++;

			QueueFree();
		}
		else
		{
			GD.Print("Not a character");
		}
	}
}