add ESC exit handler

Assets/Scripts/ExitHandles.cs

@@ -0,0 +1,21 @@
+using UnityEngine;
+
+public class ExitHandles : MonoBehaviour
+{
+    private void FixedUpdate()
+    {
+        if (Input.GetKeyDown(KeyCode.Escape))
+        {
+            QuitGame();
+        }
+    }
+
+    private void QuitGame()
+    {
+        Application.Quit();
+
+#if UNITY_EDITOR
+        UnityEditor.EditorApplication.isPlaying = false;
+#endif
+    }
+}

Assets/Scripts/ExitHandles.cs.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 5384884ed8e0b864cb4f90b078206b62