diff --git a/Assets/Scripts/LevelConfig/WaveObserver.cs b/Assets/Scripts/LevelConfig/WaveObserver.cs
index 04eda44..f1ee0e3 100644
--- a/Assets/Scripts/LevelConfig/WaveObserver.cs
+++ b/Assets/Scripts/LevelConfig/WaveObserver.cs
@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using UnityEngine;
+using System;
 
 public class WaveObserver : Singleton<WaveObserver>
 {
@@ -9,6 +10,7 @@ public class WaveObserver : Singleton<WaveObserver>
     private WaveConfig _levelConfig;
     private const int MAXTOUGHNESS = 10;
     private int _spawnerTiming = 0;
+    private List<int> _intervalTiming = new List<int>();
     public WaveConfig LevelConfig
     {
         set
@@ -22,16 +24,23 @@ public class WaveObserver : Singleton<WaveObserver>
         }
     }
 
+    /**
+     * Called by spawner at the start of the game
+     * Assigns enemy to spawn and registers them
+     */
     public void Attach(SpawnerTile spawnerSubject)
     {
 
         spawnerSubject.Prefab = _levelConfig.GetRandomSpawn().GetEnemyObject();
-        spawnerSubject.ChangeSpawnSpeed(_levelConfig.GetInterval() * ++_spawnerTiming);
         _subjects.Add(spawnerSubject);
         _aliveEnemyCount.Add(0);
-        Debug.Log("Je suis le " + _spawnerTiming + "e a agir!!!");
+        _intervalTiming.Add(++_spawnerTiming);
     }
 
+    /**
+     * Called by spawner when making enemies
+     * Assigns a new interval
+     */
     public void NotifySpawned(SpawnerTile spawnerSubject)
     {
         GameObject paramPrefab = spawnerSubject.Prefab;
@@ -43,7 +52,7 @@ public class WaveObserver : Singleton<WaveObserver>
             {
                 if (_levelConfig.ConstantSpawn[i].GetEnemyObject() == paramPrefab)
                 {
-                    currentCount = _copyConstantSpawn[i]--;
+                    currentCount = --_copyConstantSpawn[i];
                     break;
                 }
             }
@@ -60,6 +69,10 @@ public class WaveObserver : Singleton<WaveObserver>
         }
     }
 
+    /**
+     * Called by enemy when they spawn
+     * Keeps track of their row
+     */
     public int NotifyEnemy(float yPosition, float toughness)
     {
         int index = FindEnemyIndex(yPosition);
@@ -71,6 +84,10 @@ public class WaveObserver : Singleton<WaveObserver>
         return index;
     }
 
+    /**
+     * Called when an enemy dies
+     * Reactivates spawning on that row if disabled before
+     */
     public void NotifyDies(int position, float toughness)
     {
         _aliveEnemyCount[position] -= toughness;
@@ -78,22 +95,23 @@ public class WaveObserver : Singleton<WaveObserver>
         {
             _subjects[position].StartSpawn();
         }
-        Debug.Log("Fallen monster ");
     }
 
     /**
      * Called when an enemy is spawned automatically at the start of the game
      * Adjusts the intervall between spawns
      */
-    public void NotifyOnStart()
+    public void NotifyOnStart(SpawnerTile spawnerSubject)
     {
         float interval = _levelConfig.GetUpdatedInterval();
         foreach (var subject in _subjects)
         {
             subject.ChangeSpawnSpeed(interval);
         }
+        NotifySpawned(spawnerSubject);
     }
 
+    // To find which spawner an ennemy came from.
     private int FindEnemyIndex(float yPosition)
     {
         for (int i = 0; i < _subjects.Count; i++)
@@ -105,4 +123,20 @@ public class WaveObserver : Singleton<WaveObserver>
         }
         return -1;
     }
+
+    /**
+     * Spawners wait 1 second to have time to register them all
+     * Then gets assigned a random spawn interval
+     */
+    public void NotifyEndCooldown(SpawnerTile spawnerTile)
+    {
+        System.Random rand = new System.Random();
+        int index;
+        do
+        {
+            index = rand.Next(_subjects.Count);
+        } while (_intervalTiming.Count <= index);
+        spawnerTile.ChangeSpawnSpeed(_levelConfig.GetInterval() * _intervalTiming[index]);
+        _intervalTiming.Remove(index);
+    }
 }
diff --git a/Assets/Scripts/Opponent/Opponent.cs b/Assets/Scripts/Opponent/Opponent.cs
index e8b686e..24cd742 100644
--- a/Assets/Scripts/Opponent/Opponent.cs
+++ b/Assets/Scripts/Opponent/Opponent.cs
@@ -52,7 +52,7 @@ public class Opponent : Entity
             AttackSpeedWait += Time.deltaTime;
     }
 
-    private void OnDisable()
+    private void OnDestroy()
     {
         _observer.NotifyDies(_observerIndex, _toughness);
     }
diff --git a/Assets/Scripts/Tiles/SpawnerTile.cs b/Assets/Scripts/Tiles/SpawnerTile.cs
index e79be65..38450a7 100644
--- a/Assets/Scripts/Tiles/SpawnerTile.cs
+++ b/Assets/Scripts/Tiles/SpawnerTile.cs
@@ -10,11 +10,12 @@ public class SpawnerTile : LevelTile
     private bool _spawnOnStart;
     private float _lifetime;
     [SerializeField]
-    private float _spawnSpeed = 0;
+    private float _spawnSpeed = 1.0f;
     [SerializeField, Range(0, 1.001f)]
     private float _spawnCounter = 0;
     private WaveObserver _observer;
-    private bool stopped = false;
+    private bool _stopped = false;
+    private bool _cooldownEnded = false;
 
 
     public override void LevelStart()
@@ -24,20 +25,26 @@ public class SpawnerTile : LevelTile
         if (_spawnOnStart && _lifetime <= 0)
         {
             _prefab.Create(Position, parent: LevelManager.Instance.LevelTransform);
-            _observer.NotifyOnStart();
+            _observer.NotifyOnStart(this);
         }
     }
 
     public override void LevelUpdate()
     {
         _lifetime += Time.deltaTime;
-        if (!stopped)
+        if (!_stopped)
         {
             _spawnCounter += Time.deltaTime;
         }
         if (_spawnCounter < _spawnSpeed) return;
 
         _spawnCounter = 0;
+        if (!_cooldownEnded)
+        {
+            _observer.NotifyEndCooldown(this);
+            _cooldownEnded = true;
+            return;
+        }
         _prefab.Create(Position, parent: LevelManager.Instance.LevelTransform);
         _observer.NotifySpawned(this);
     }
@@ -62,12 +69,12 @@ public class SpawnerTile : LevelTile
 
     internal void StopSpawn()
     {
-        stopped = true;
+        _stopped = true;
     }
 
     internal void StartSpawn()
     {
-        stopped = false;
+        _stopped = false;
     }
 
 
@@ -95,6 +102,10 @@ public class SpawnerTile : LevelTile
         }
     }
 
+    /**
+     * Called by observer
+     * Assigns a new spawn interval
+     */
     public void ChangeSpawnSpeed(float value)
     {
         _spawnSpeed = value;
diff --git a/Assets/WaveConfig/Config01.asset b/Assets/WaveConfig/Config01.asset
index 827612f..371055b 100644
--- a/Assets/WaveConfig/Config01.asset
+++ b/Assets/WaveConfig/Config01.asset
@@ -14,5 +14,5 @@ MonoBehaviour:
   m_EditorClassIdentifier: 
   _constantSpawn:
   - _enemy: {fileID: 313037212318601125, guid: 5bbf0d85fa5bb3f4599da79f0a84e3a9, type: 3}
-    _count: 20
-  _gameDuration: 3
+    _count: 5
+  _gameDuration: 1