2D Move Up and Down

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Move : MonoBehaviour {

    public float moveSpeed;

    // Use this for initialization
    void Start () {

    }

    // Update is called once per frame
    void Update () {


        if (Input.GetKey (KeyCode.UpArrow)) {
            transform.Translate (new Vector3 (0, moveSpeed, 0) * Time.deltaTime);
        }

        if (Input.GetKey (KeyCode.DownArrow)) {
            transform.Translate (new Vector3 (0,  -moveSpeed, 0) * Time.deltaTime);
        }

    }
}