if(speed >= 30){
speed = 30;
}

if(Input.GetKeyDown(KeyCode.E)){
// Действие
}

var thisObject : Transform;
var Player : GameObject;
var speed : float;

function Start(){
thisObject = transform;
Player = GameObject.FindGameObjectWithTag("Player"); // Или Player = GameObject.Find("Player");
}

function Update(){
var pos : Vector3 = Player.transform.position;
pos.y = transform.position.y;
transform.LookAt(pos);
transform.position += thisObject.forward * speed * Time.deltaTime;
}