Thanks to Yelpers, we went on a tour last weekend. The owners say they do very little advertising, most of their business is from word of mouth. I've lived in LV for 8 years and never heard of the tour before stumbling across it while looking for something unique to do with my friend for her birthday.
Our party (two couples) was joined by a third couple and a party of three girls (so 9 total in our group). My hubby was dragging his feet about going but by the time we got to the first stop, he was literally running off the bus to find clues, hahaha. Seriously THE most most fun we've had in a long time. The only bummer is that they only change the "mystery" once a year so once you've gone, you have to wait a whole year to go again!! But we can understand why, there is just so much that goes in to planning the tour.
Our driver, Max, recommended coming for our second tour in October or November (the tour changes each year in September but it takes a little while to tweak it and work out the kinks). The website says it is PG-13 and not recommended for children under 13 - I would concur, leave the kiddies at home for this one. That's all I can say, don't want to give anything away!!
I highly recommend Mystery Adventure Tours!