player mouse rotation, 2D twin shooter. player won't rotate.

Hey guys, I'm trying to get my player ship to rotate with my mouse. I've checked and re-checked and still can't get it to work. The player is a 2D sprite currently in a 'still' position and haha, just won't move. My background and player are in reset positions. Here's the coding below, I hope someone has an idea or sees something that can be fixed, it has been pretty frustrating. Thanks in advance.

 void Update ()
 {
     Rotation ();
 }

 //rotate player to face mouse
 void Rotation ()
     {
     //finding where the mouse is relative to the player
     Vector3 worldPos = Input.mousePosition;
     worldPos = Camera.main.ScreenToWorldPoint(worldPos);

     //get the difference from each axis (delta x and y)
     float dx = this.transform.position.x - worldPos.x;
     float dy = this.transform.position.y - worldPos.y;

     //get the angle between the two objects
     float angle = Mathf.Atan2(dy, dx) * Mathf.Rad2Deg;

     Quaternion rotation = Quaternion.Euler(new Vector3(0, 0, angle));


         // Assign the ship's rotation
     this.transform.rotation = rotation;

     }