particles/ParticleNode.cs

using Godot;

// ReSharper disable once CheckNamespace
// ReSharper disable once ClassNeverInstantiated.Global
public class ParticleNode : Node2D
{
    private Label _labelNode;
    private Sprite _spriteNode;
    public Vector2 CurrentSimulationPosition = new Vector2();

    public Vector2 LastSimulationPosition;
    public bool WasTeleportedLast = true;
    public int SimulationId;

    public override void _Ready()
    {
        _spriteNode = GetNode<Sprite>("Sprite");
        _labelNode = GetNode<Label>("Label");
    }

    public override void _Process(float delta)
    {
        Position = WasTeleportedLast == false
            ? LastSimulationPosition.LinearInterpolate(CurrentSimulationPosition,
                GetParent<Node2D>().GetParent<ParticleSimulationScene>().PhysicsInterpolationFraction)
            : CurrentSimulationPosition;
    }

    public void SetLabelText(string text)
    {
        _labelNode.Text = text;
    }

    public void SetColor(float hue, float saturation, float opacity)
    {
        _spriteNode.Modulate = Color.FromHsv(hue, saturation, 1, opacity);
    }
}