Создание змейки на Unity2D

public void Spawn() {
    // x position between left & right border
    int x = (int)Random.Range(borderLeft.position.x + 1,
                              borderRight.position.x - 1);
 
    // y position between top & bottom border
    int y = (int)Random.Range(borderBottom.position.y + 1,
                              borderTop.position.y - 1);
 
    // Instantiate the food at (x, y)
    Instantiate(foodPrefab,
                new Vector2(x, y),
                Quaternion.identity); // default rotation
}

    // Update is called once per frame
    void Update ()
    {
        var h = Input.GetAxisRaw("Horizontal");
        var v = Input.GetAxisRaw("Vertical");
 
        if (v > 0 && (dir != Vector2.down))
        {
            dir = Vector2.up;
        }
        else if (v < 0 && (dir != Vector2.up))
        {
            dir = Vector2.down;
        }
 
        if (h < 0 && (dir != Vector2.right))
        {
            dir = Vector2.left;
        }
        else if (h > 0 && (dir != Vector2.left))
        {
            dir = Vector2.right;
        }
    }

    // Update is called once per frame
    void Update()
    {
        // Move in a new Direction?
        if (Input.GetKey(KeyCode.RightArrow) && (dir != Vector2.left))
            dir = Vector2.right;
        else if (Input.GetKey(KeyCode.DownArrow) && (dir != Vector2.up))
            dir = -Vector2.up;    // '-up' means 'down'
        else if (Input.GetKey(KeyCode.LeftArrow) && (dir != Vector2.right))
            dir = -Vector2.right; // '-right' means 'left'
        else if (Input.GetKey(KeyCode.UpArrow) && (dir != Vector2.down))
            dir = Vector2.up;
    }

using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement;
 
public class UIManager : MonoBehaviour
{
    public void OnClickStartButton()
    {
        SceneManager.LoadScene("Level001");
    }
 
    public void OnClickExitButton()
    {
        Application.Quit();
    }
}

using UnityEngine;
using System.Collections;
using UnityEngine.SceneManagement;
 
public class UIManager : MonoBehaviour
{
    public void OnClickStartButton()
    {
        SceneManager.LoadScene("Level001");
    }
 
    public void OnClickExitButton()
    {
        Application.Quit();
    }
 
    public void OnClickTryAgainButton()
    {
        SceneManager.LoadScene("Menu");
    }
}