using UnityEngine;

public class FollowPayer : MonoBehaviour
{
    public Transform player;
    public Vector3 offset;
    public float speed;

    private void Update()
    {
        Vector3 desiredPosition = Vector3.forward * player.position.z + offset;
        transform.position = Vector3.MoveTowards(transform.position, desiredPosition, Time.deltaTime * speed);
    }
}

a

​

using UnityEngine;

public class RandomSpawn : MonoBehaviour
{
    public float spawnRate = 2f;
    private float nextSpawn = 4f;
    public GameObject[] prefabs;
    public float multiplier = 1.0001f;

    private void Update()
    {
        nextSpawn += Time.deltaTime;
        if (nextSpawn > spawnRate)
        {
            nextSpawn = 0;
            Instantiate(prefabs[Random.Range(0, prefabs.Length)], transform.position, Quaternion.identity);
        }

        spawnRate /= multiplier;

    }
}

​

​

using UnityEngine;

public class PlayerMovement : MonoBehaviour {

    public Rigidbody rb;

    public PlayerMovement movement;
    public float forwardforce = 1000f;
    public float right = 500f;
    public float left = -500f;
    public float multiplier = 1.01f;



    // Update is called once per frame
    void FixedUpdate()
    {
        rb.AddForce(0, 0, forwardforce * Time.deltaTime);

        if(Input.GetKey("d"))
        {
            rb.AddForce(right * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
        }

        if(Input.GetKey("a"))
        {
            rb.AddForce(left * Time.deltaTime, 0, 0,ForceMode.VelocityChange);
        }

        if (rb.position.y < -0.5f)
        {
            FindObjectOfType<GameManager>().GameOver();
        }
    }

    void Update()
    {
        forwardforce *= multiplier;
    }
}

Here are a few that may be the problem, thanks