Added high score

Also made player always render on top of enemies

Assets/Scripts/EnemyController.cs

@@ -14,7 +14,7 @@ public class EnemyController : OrbitalPositionBehaviour
     public override void OnReachCentre()
     {
         if (GlobalOrbitalPositionManager.IsSimulationRunning)
-            PlayerController.PlayerScore++;
+            PlayerController.s_PlayerScore++;
         
         Destroy(gameObject);
     }