This place is pretty easy to find. Just go up the escalator to the 3rd floor and you can see the "hidden" passageway.
The place is relatively small with counters along the side for you to eat your pizza and go. I thought the pizza was pretty standard. It didn't taste particularly amazing to me, but maybe its just me.
I thought their prices were pretty steep for a whole pie. Be prepared to wait if you decide to go this route. There are some pin ball machines that can entertain you while you wait. Individual slices seem like the better and faster deal. Soda is served in a red dixie cup and not worth what they charge.