Unity Player Script

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Experimental.Input;
[RequireComponent(typeof(Rigidbody))]


public class PlayerScript : MonoBehaviour
{
    public int points = 0;


    public Vector3 jump;
    public float jumpForce = 5.0f;


    public bool isGrounded;
    Rigidbody rb;

    public GUIStyle customGUI;






    void Start()
    {
        rb = GetComponent<Rigidbody>();
        jump = new Vector3(0.0f, 5.0f, 0.0f);


    }

    void OnCollisionStay()
    {
        isGrounded = true;
    }




    void Update()
    {
        if (Input.GetKeyDown(KeyCode.Space) && isGrounded)
        {

            rb.AddForce(jump * jumpForce, ForceMode.Impulse);
            isGrounded = false;
        }
    }
    private void OnGUI()
    {

        GUI.Label(new Rect(20,20,150,20),"SCORE : " + points + "/50", customGUI);

        if (points >= 50)
        {
            GUI.Label(new Rect(700, 300, 150, 20), "YOU WIN!" , customGUI);
        }



    }
}