I've only been once but it's going to be a regular stop every visit to Vegas from now on, I could spend entire afternoon there. Last trip I ended up playing the centipede game for the last hour, had a blast. Man, that place brought back a lot of memory's.
That loud knock you hear when a free game is won is caused by a little 'hammer' that knock's the side of the wooden case, I saw it on one of those how it's made shows on discovery,science or one of those channels.
J