Добавил переключение режима после уничтожения последного врага

Assets/Scenes/Island.unity

@@ -4219,6 +4219,7 @@ GameObject:
   - component: {fileID: 694046009}
   - component: {fileID: 694046008}
   - component: {fileID: 694046010}
+  - component: {fileID: 694046011}
   m_Layer: 0
   m_Name: EnemySpawner
   m_TagString: Untagged
@@ -4273,12 +4274,25 @@ MonoBehaviour:
   m_Script: {fileID: 11500000, guid: 584d2a34a7bab574594a37606a39be8e, type: 3}
   m_Name: 
   m_EditorClassIdentifier: Assembly-CSharp::SpawnDeathEnemyController
-  _gameManager: {fileID: 1875710079}
   _enemySpawner: {fileID: 694046008}
   _wallet: {fileID: 1030979928}
   _onLastEnemyDestroyed:
     m_PersistentCalls:
       m_Calls: []
+--- !u!114 &694046011
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 694046007}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: 78768dd3999d2ea4a80ad7a46bbf27a6, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: Assembly-CSharp::EndWaveStateSwitch
+  _gameManager: {fileID: 1875710079}
+  _spawnDeathEnemyController: {fileID: 694046010}
 --- !u!1001 &697685528
 PrefabInstance:
   m_ObjectHideFlags: 0

Assets/Scripts/EndWaveStateSwitch.cs

@@ -0,0 +1,23 @@
+using UnityEngine;
+using System.Collections;
+
+public class EndWaveStateSwitch : MonoBehaviour
+{
+    [SerializeField] private GameManager _gameManager;
+    [SerializeField] private SpawnDeathEnemyController _spawnDeathEnemyController;
+
+    private void OnEnable()
+    {
+        _spawnDeathEnemyController.OnLastEnemyDestroyed += OnLastEnemyDestroyed;
+    }
+
+    private void OnDisable()
+    {
+        _spawnDeathEnemyController.OnLastEnemyDestroyed -= OnLastEnemyDestroyed;
+    }
+
+    private void OnLastEnemyDestroyed()
+    {
+        _gameManager.CurrentState = GameManager.GameState.BuildingTurrets;
+    }
+}

Assets/Scripts/EndWaveStateSwitch.cs.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 78768dd3999d2ea4a80ad7a46bbf27a6

Assets/Scripts/SpawnDeathEnemyController.cs

@@ -4,7 +4,6 @@ using UnityEngine.Events;
 
 public class SpawnDeathEnemyController : MonoBehaviour
 {
-    [SerializeField] private GameManager _gameManager;
     [SerializeField] private EnemySpawner _enemySpawner;
     [SerializeField] private Wallet _wallet;
     [SerializeField] private UnityEvent _onLastEnemyDestroyed;