Не работает скрипт в Unity

Недавно начал учиться созданию игр на unity
Для начала я решил найти скрипт на передвижение персонажа в интернете, нашел его, скопировал, исправил все ошибки, импортировал, но все равно ничего не работает ,
Для работы со скриптом использую Visual studio 2019
Пишу на языке c#
вот скрипт, тот кто скажет в чем проблема буду крайне признателен .
using UnityEngine;
using System.Collections;

[RequireComponent(typeof(Rigidbody2D))]

public class Player2DControl : MonoBehaviour {

public enum ProjectAxis {onlyX = 0, xAndY = 1};
public ProjectAxis projectAxis = ProjectAxis.onlyX;
public float speed = 150;
public float addForce = 7;
public bool lookAtCursor;
public KeyCode leftButton = KeyCode.A;
public KeyCode rightButton = KeyCode.D;
public KeyCode upButton = KeyCode.W;
public KeyCode downButton = KeyCode.S;
public KeyCode addForceButton = KeyCode.Space;
public bool isFacingRight = true;
private Vector3 direction;
private float vertical;
private float horizontal;
private Rigidbody2D body;
private float rotationY;
private bool jump;

void Start ()
{
body = GetComponent();
body.fixedAngle = true;

if(projectAxis == ProjectAxis.xAndY)
{
body.gravityScale = 0;
body.drag = 10;
}
}

void OnCollisionStay2D(Collision2D coll)
{
if(coll.transform.tag == "Ground")
{
body.drag = 10;
jump = true;
}
}

void OnCollisionExit2D(Collision2D coll)
{
if(coll.transform.tag == "Ground")
{
body.drag = 0;
jump = false;
}
}

void FixedUpdate()
{
body.AddForce(direction * body.mass * speed);

if(Mathf.Abs(body.velocity.x) > speed/100f)
{
body.velocity = new Vector2(Mathf.Sign(body.velocity.x) * speed/100f, body.velocity.y);
}

if(projectAxis == ProjectAxis.xAndY)
{
if(Mathf.Abs(body.velocity.y) > speed/100f)
{
body.velocity = new Vector2(body.velocity.x, Mathf.Sign(body.velocity.y) * speed/100f);
}
}
else
{
if(Input.GetKey(addForceButton) && jump)
{
body.velocity = new Vector2(0, addForce);
}
}
}

void Flip()
{
if(projectAxis == ProjectAxis.onlyX)
{
isFacingRight = !isFacingRight;
Vector3 theScale = transform.localScale;
theScale.x *= -1;
transform.localScale = theScale;
}
}

void Update ()
{
if(lookAtCursor)
{
Vector3 lookPos = Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, Camera.main.transform.position.z));
lookPos = lookPos - transform.position;
float angle = Mathf.Atan2(lookPos.y, lookPos.x) * Mathf.Rad2Deg;
transform.rotation = Quaternion.AngleAxis(angle, Vector3.forward);
}

if(Input.GetKey(upButton)) vertical = 1;
else if(Input.GetKey(downButton)) vertical = -1; else vertical = 0;

if(Input.GetKey(leftButton)) horizontal = -1;
else if(Input.GetKey(rightButton)) horizontal = 1; else horizontal = 0;

if(projectAxis == ProjectAxis.onlyX)
{
direction = new Vector2(horizontal, 0);
}
else
{
if(Input.GetKeyDown(addForceButton)) speed += addForce; else if(Input.GetKeyUp(addForceButton)) speed -= addForce;
direction = new Vector2(horizontal, vertical);
}

if(horizontal > 0 && !isFacingRight) Flip(); else if(horizontal < 0 && isFacingRight) Flip();
}
}