Simple controller script for Unity3D (5.x)

PlayerController.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerController : MonoBehaviour {
	// Update is called once per frame
	void Update () {
        this.transform.Translate(new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical")) * Time.deltaTime);
	}
}