How to rotate 2D object with mouse?

Hello, i'm making my first 2D game, i want to make a script that makes player arms with the rocket launcher aim to the mouse position from the rocket launcher, the problem is that i need it to get the position from rocket launcher and rotate arms with rocket launcher object. I couldn't figure it out, hope there is a way to do it.

I had made a script that does it but it rotated the object to the wrong position so it wasn't very precise so i found much easier one but it doesn't rotate to the position i want, yet, hopefully. Here is the new script :

Code (CSharp):

1. //Gets the mouse position
2. mousePosition = camera.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, Input.mousePosition.z - camera.transform.position.z));
3.  
4. //Draws a ray from the pivot point from object to the mouse position
5. Debug.DrawRay(transform.position, mousePosition - transform.position, Color.cyan);
6.  
7. //Rotates the object
8. transform.rotation = Quaternion.LookRotation(Vector3.forward, mousePosition - transform.position);

So basically i want to rotate the player arms with rocket launcher to the mouse position from rocket launcher if that makes sense.

 

Try this, c# and js versions.

 

Thank you so much, that's exactly what i wanted!!!