test.cs

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

public class Move : MonoBehaviour
{
	public GameObject myMissile;

    // Use this for initialization
    void Start()
    {

    }

    // Update is called once per frame
    void Update()
    {
        if (transform.position.x > -11)
        {
            if (Input.GetKey(KeyCode.LeftArrow))
            {
                Vector2 v = new Vector2(Time.deltaTime * -8, 0);
                transform.Translate(v);
            }
        }

        if (transform.position.x < 11)
        {
            if (Input.GetKey(KeyCode.RightArrow))
            {
                Vector2 v = new Vector2(Time.deltaTime * 8, 0);
                transform.Translate(v);
            }
        }

		if (Input.GetKeyDown(KeyCode.Space)) {
			Vector2 v = new Vector2(transform.position.x, 0.5f);
			Instantiate(myMissile, v, Quaternion.identity);
		}
    }
}