I first tried this place a couple weeks ago after a late night in Vegas. It's hidden away down a hallway with no sign or advertisement to tell you it's there. The place has a old school feel to it. In the hallway, the walls are covered with old album covers. They also have arcade games and pinball machines. It's really small, so don't count on eating in there unless it's not too busy.
The line was pretty long when I went especially considering it was 2:00 am, but the pizza was worth the 15 minute wait. I got 2 slices of pizza ($5.50 each). One had pepperoni and banana peppers and the other had white cheese. The pepperoni and banana peppers slice was good, but the white cheese pizza I think is the one everyone should try if they come here.
Overall, it's easy to see why people love this place: it's open basically all night, there's mystery surrounding it being "secret", and its old school theme is really cool. In my opinion, the pizza itself is above average, but not amazing. If this review was strictly about the pizza and the price, then I'd probably give them 3 stars. This is a place I do look forward to showing some friends and returning too next time I'm out late in Vegas. Try them out!