using UnityEngine;

public class EnemyEyes : MonoBehaviour
{
    public GameObject Target { get; private set; }   // читать всем, менять — только тут

    private void OnTriggerEnter2D(Collider2D other)
    {
        if (other.CompareTag("Player"))
            Target = other.gameObject;
    }

    private void OnTriggerExit2D(Collider2D other)
    {
        if (other.CompareTag("Player"))
            Target = null;                            // уплыл — забыли
    }
}

using UnityEngine;

public class EnemyMovement : MonoBehaviour
{
    [SerializeField] private float speed = 1.5f;
    [SerializeField] private float chaseSpeed = 3f;
    [SerializeField] private EnemyEyes eyes;

    private Rigidbody2D body;

    private void Awake() => body = GetComponent<Rigidbody2D>();

    private void FixedUpdate()
    {
        if (eyes.Target != null)
        {
            Vector2 dir = (eyes.Target.transform.position - transform.position).normalized;
            transform.right = dir;
            body.linearVelocity = dir * chaseSpeed;
        }
        else
        {
            body.linearVelocity = transform.right * speed;
        }
    }
}

using UnityEngine;

public class EnemyRotation : MonoBehaviour
{
    [SerializeField] private float rotateTime = 2f;
    [SerializeField] private EnemyEyes eyes;

    private float timer = 0f;
    private SpriteRenderer sr;

    private void Start() => sr = GetComponent<SpriteRenderer>();

    private void Update()
    {
        if (eyes.Target == null)          // курс меняем, только когда никого не видим
        {
            timer -= Time.deltaTime;
            if (timer <= 0f)
            {
                Vector3 look = Random.insideUnitCircle;
                look.z = 0f;
                transform.right = look;
                timer = rotateTime;
            }
        }

        sr.flipY = transform.right.x < 0f;   // анти-кувырок
    }
}