2d rotation to face player at mouse

I am trying to make a 2d top down shooter and i want the controls to be where you can just move forward and backward and then you can move the mouse to rotate the player to face the mouse. I have an empty game object that move where the mouse is. This is what my code looks like:

public var target : Transform;

function Update()
{
transform.LookAt(target);
}

I thought this would work. Everything that I tried was buggy. This will move the camera back and forth between the front of the player and behind. It also doesn't rotate enough to be pointing at the mouse. Please help!

 

I believe it's because LookAt rotates an object on the z-axis by default. You need to specify a different axis since you're using 2D.

 

how do you specify that? @mafiadude1

 

LookAt(Transform target, Vector3 worldUp = Vector3.up)

 

You also do the math yourself and set the rotation that way?