Добавил таймер для автоматического переключения волн

Assets/Scripts/TurretsBuildTimer.cs

@@ -0,0 +1,60 @@
+using UnityEngine;
+using System.Collections;
+using UnityEngine.Events;
+
+public class TurretsBuildTimer : MonoBehaviour
+{
+    [SerializeField] private GameManager _gameManager;
+    [SerializeField] private float _buildTime = 10f;
+    [SerializeField] private UnityEvent<OnTickEventArgs> _onTick;
+
+    public event UnityAction<OnTickEventArgs> OnTick
+    {
+        add => _onTick.AddListener(value);
+        remove => _onTick.RemoveListener(value);
+    }
+
+    private static readonly WaitForSeconds _wait = new(1f);
+
+    private void OnEnable()
+    {
+        _gameManager.OnStateChanged += OnStateChanged;
+    }
+
+    private void OnDisable()
+    {
+        _gameManager.OnStateChanged -= OnStateChanged;
+    }
+
+    private void OnStateChanged(GameManager.GameState newState)
+    {
+        if (newState == GameManager.GameState.BuildingPath)
+            return;
+
+        StopCoroutine(nameof(Timer));
+        if (newState == GameManager.GameState.BuildingTurrets)
+            StartCoroutine(nameof(Timer));
+    }
+
+    private IEnumerator Timer()
+    {
+        for (float i = 0; i < _buildTime; i++)
+        {
+            _onTick?.Invoke(new OnTickEventArgs
+            {
+                ElapsedSeconds = i,
+                TotalSeconds = _buildTime
+            });
+            yield return _wait;
+        }
+
+        _gameManager.NextLevel();
+    }
+
+    public class OnTickEventArgs
+    {
+        public float SecondsLeft => TotalSeconds - ElapsedSeconds;
+        public float ElapsedSeconds { get; set; }
+        public float TotalSeconds { get; set; }
+    }
+}

Assets/Scripts/TurretsBuildTimer.cs.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 330d868d3d6a72c489dce65e1ca03edc