Поймай её

using UnityEngine;

public class Catcher : MonoBehaviour
{
    [SerializeField] private float speed = 6f;
    [SerializeField] private Transform star;
    [SerializeField] private float fallSpeed = 3f;

    void Update()
    {
        float x = transform.position.x;
        if (Input.GetKey(KeyCode.RightArrow))
        {
            x += speed * Time.deltaTime;
        }
        if (Input.GetKey(KeyCode.LeftArrow))
        {
            x -= speed * Time.deltaTime;
        }
        x = Mathf.Clamp(x, -4f, 4f);
        transform.position = new Vector3(x, transform.position.y, transform.position.z);

        star.position += Vector3.down * fallSpeed * Time.deltaTime;
    }
}