campfire/Assets/Scripts/PauseMenu.cs

using UnityEngine;

[RequireComponent(typeof(CanvasGroup))]
public class PauseMenu : MonoBehaviour {
    public GameState GameState;

    private CanvasGroup Canvas;
    private bool Paused {
        get {
            return GameState.Current == State.Paused;
        }
    }

    private void Awake() {
        Canvas = GetComponent<CanvasGroup>();
        Canvas.alpha = Paused ? 1 : 0;
    }

    private void Update() {
        Canvas.alpha = Mathf.Lerp(Canvas.alpha, Paused ? 1 : 0, 10f * Time.unscaledDeltaTime);
    }
}