EntityController.cs
using Sandbox;

public sealed class EntityController : Component
{
	[Property]
    public RedLightGreenLight GameController { get; set; }

	protected override void OnUpdate()
	{
		if ( GameController.State == RedLightGreenLight.GameState.Red)
		{
			GameObject.Transform.Rotation = Rotation.FromYaw(180f);
			Log.Info("entity red");
		}
		else
		{
			GameObject.Transform.Rotation = Rotation.FromYaw(0f);
			Log.Info("entity green");
		}
	}

	[Button]
	public void Rotate()
	{
		GameObject.Transform.Rotation = Rotation.FromYaw(0f);

	}
}