The Fun Dungeon is located downstairs in the Excalibur Hotel and is a great place for kids and adults alike to take a break from the constant cigarette smoke and "pinging" of slot machines and enjoy other wholesome activities like shooting aliens in the face or feverishly collecting tickets!
In all honesty though, this arcade is full of both classic and new games that will entertain the pickiest of kids and the most boring of adults. My favorite game was the motorcycle game, in which I climbed onto a life-size replica of an actual motorcycle and twisted and turned my way through the obstacles on the screen in front of me.
Be prepared to bring some cash. I spent $25 to get enough quarters to last about an hour and a half between my five-year-old charge and myself, but that's cheap enough for Vegas!
Very fun.