Simple AI In 2D - C#

Im making a simple free roam spaceship game, and all i need is the alien to move towards me, i only know how to do this in 3d, ive sorted out the rotation bit(with help) so it always points towards me, but how can I make it move towards me, because at the movement im telling it to go foward , but our Z angles are equal?? Can i make it so that it follows my X+Y?? Just Look :

using UnityEngine;
using System.Collections;

public class EnemyAI : MonoBehaviour {
	public Transform target;
	public int moveSpeed;
	public int rotationSpeed;

	private Transform myTransform;

	// Use this for initialization
	void Awake() {
		myTransform = transform;

	void Start () {
		GameObject go = GameObject.FindGameObjectWithTag("Player");

		target = go.transform;
	// Update is called once per frame
	void Update () {	
		Vector3 dir = target.position - myTransform.position;
		dir.z = 0.0f; // Only needed if objects don't share 'z' value
		if (dir != {
			myTransform.rotation = Quaternion.Slerp (myTransform.rotation, 
			                                         Quaternion.FromToRotation(Vector3.right, dir), rotationSpeed * Time.deltaTime);

			//Move Towards Target
		myTransform.position += myTransform.position * moveSpeed * Time.deltaTime;

Change line 32:

myTransform.position += (target.position - myTransform.position).normalized * moveSpeed * Time.deltaTime;