时间计时器当时间超过60s时游戏结束

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

using UnityEngine.UI;

public class time : MonoBehaviour

{

   public int a;

   public float now_time;

   // Start is called before the first frame update

   void Start()

   {

       

   }

   // Update is called once per frame

   void Update()

   {

       now_time += Time.deltaTime;

       a = (int)now_time;

       if(a < 61)

       {

           this.gameObject.GetComponent<Text>().text = a.ToString();

       }

       else if(a > 61)

       {

           this.gameObject.GetComponent<Text>().text = "Gameover";

       }

   }

}