private void _EndOverdrive()
 {
     _State = OverdriveState.Available;
     if (_LastLevelMode == OverdriveMode.Level)
     {
         PrevLevel();
         CurrentLevel.Mode = OverdriveMode.Multiplier;
     }
     else if (_LastLevelMode == OverdriveMode.Multiplier)
     {
         CurrentLevel.Normalize();
         if (CanPrevLevel)
         {
             PrevLevel();
         }
         else
         {
             CurrentLevel.Cripple();
             _State = OverdriveState.Unavailable;
         }
     }
 }