World Movement

using UnityEngine;
using System.Collections;

public class WorldMovement : MonoBehaviour {

    private PlayerMovement player;
    private float speed;

    void Awake()
    {
        PlayerMovement p = FindObjectOfType<PlayerMovement>();
        if (p == null)
        {
            Debug.LogWarning("No player in scene!");
        }
        else
        {
            player = p;
        }
    }

    void Update()
    {
        speed = player.speed;
        MoveChildren();
    }

    void MoveChildren()
    {
        for (int i = 0; i < transform.childCount; i++)
        {
            transform.GetChild(i).Translate(new Vector3(0, 0, -speed * Time.deltaTime));
        }
    }
}