diff --git a/Engine.Physics2D/PhysicsEngine2D.cs b/Engine.Physics2D/PhysicsEngine2D.cs
index 62d309b..511ecd0 100644
--- a/Engine.Physics2D/PhysicsEngine2D.cs
+++ b/Engine.Physics2D/PhysicsEngine2D.cs
@@ -28,21 +28,21 @@ public class PhysicsEngine2D : UniverseObject, IPhysicsEngine2D
     {
         float intervalDeltaTime = deltaTime / IterationPerStep;
 
-        foreach (IPrePhysicsUpdate physicsPreUpdate in physicsPreUpdateCollector)
-            physicsPreUpdate.PrePhysicsUpdate(deltaTime);
+        for (int i = physicsPreUpdateCollector.Behaviours.Count - 1; i >= 0; i--)
+            physicsPreUpdateCollector.Behaviours[i].PrePhysicsUpdate(deltaTime);
 
-        foreach (IPhysicsUpdate physicsUpdate in physicsUpdateCollector)
-            physicsUpdate.PhysicsUpdate(deltaTime);
+        for (int i = physicsUpdateCollector.Behaviours.Count - 1; i >= 0; i--)
+            physicsUpdateCollector.Behaviours[i].PhysicsUpdate(deltaTime);
 
         for (int iterationIndex = 0; iterationIndex < IterationPerStep; iterationIndex++)
         {
             // Can Parallel
-            foreach (IRigidBody2D rigidBody in rigidBodyCollector)
-                StepRigidBody(rigidBody, intervalDeltaTime);
+            for (int i = rigidBodyCollector.Behaviours.Count - 1; i >= 0; i--)
+                StepRigidBody(rigidBodyCollector.Behaviours[i], intervalDeltaTime);
 
             // Can Parallel
-            foreach (ICollider2D collider in colliderCollector)
-                collider.Recalculate();
+            for (int i = colliderCollector.Behaviours.Count - 1; i >= 0; i--)
+                colliderCollector.Behaviours[i].Recalculate();
 
             // Can Parallel
             for (int x = 0; x < colliderCollector.Behaviours.Count; x++)
@@ -65,8 +65,8 @@ public class PhysicsEngine2D : UniverseObject, IPhysicsEngine2D
             OnPhysicsIteration?.Invoke(this, intervalDeltaTime);
         }
 
-        foreach (IPostPhysicsUpdate physicsPostUpdate in physicsPostUpdateCollector)
-            physicsPostUpdate.PostPhysicsUpdate(deltaTime);
+        for (int i = physicsPostUpdateCollector.Behaviours.Count - 1; i >= 0; i--)
+            physicsPostUpdateCollector.Behaviours[i].PostPhysicsUpdate(deltaTime);
 
         OnPhysicsStep?.Invoke(this, deltaTime);
     }
@@ -95,8 +95,8 @@ public class PhysicsEngine2D : UniverseObject, IPhysicsEngine2D
         {
             StepRigidBody(rigidBody, intervalDeltaTime);
 
-            foreach (ICollider2D collider in childColliders)
-                collider.Recalculate();
+            for (int i = childColliders.Count - 1; i >= 0; i--)
+                childColliders[i].Recalculate();
 
             for (int x = 0; x < childColliders.Count; x++)
             {
diff --git a/Engine.Physics2D/PhysicsEngine2DStandalone.cs b/Engine.Physics2D/PhysicsEngine2DStandalone.cs
index dbe160d..375ed60 100644
--- a/Engine.Physics2D/PhysicsEngine2DStandalone.cs
+++ b/Engine.Physics2D/PhysicsEngine2DStandalone.cs
@@ -45,12 +45,12 @@ public class PhysicsEngine2DStandalone : IPhysicsEngine2D
         for (int iterationIndex = 0; iterationIndex < IterationPerStep; iterationIndex++)
         {
             // Can Parallel
-            for (int i = 0; i < rigidBodies.Count; i++)
+            for (int i = rigidBodies.Count - 1; i >= 0; i--)
                 StepRigidBody(rigidBodies[i], intervalDeltaTime);
 
             // Can Parallel
-            foreach (ICollider2D collider in colliders)
-                collider.Recalculate();
+            for (int i = colliders.Count - 1; i >= 0; i--)
+                colliders[i].Recalculate();
 
             // Can Parallel
             for (int x = 0; x < colliders.Count; x++)