PlayControllor.cs

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

[System.Serializable]
public class Boundary
{
    public float xMin, xMax, zMin, zMax;
}

public class PlayControllor : MonoBehaviour
{
    public Rigidbody rb;
    public float speed;
    public Boundary boundary;
    public float tilt;

    public GameObject shot;
    public Transform shotSpawn;
    public float fireRate;

    private float nextFire;

    void Start()
    {
        rb = GetComponent<Rigidbody>();
    }

    void Update()
    {
        if (Input.GetButton("Fire1") && Time.time > nextFire)
        {
            nextFire = Time.time + fireRate;
            Instantiate(shot, shotSpawn.position, shotSpawn.rotation);

            GetComponent<AudioSource>().Play();//新版本要写的，原版Audio.Play();
        }
    }

    void FixedUpdate(){
		float moveHorizontal = Input.GetAxis ("Horizontal");
		float moveVertical = Input.GetAxis ("Vertical");

        Vector3 movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);
        rb.velocity = movement * speed;

        rb.position = new Vector3
       (
           Mathf.Clamp(rb.position.x, boundary.xMin, boundary.xMax),
           0.0f,
           Mathf.Clamp(rb.position.z, boundary.zMin, boundary.zMax)
       );

        rb.rotation = Quaternion.Euler(0.0f, 0.0f, rb.velocity.x * -tilt);
    }
}