Our daughter was 2 years old when we were visiting Vegas. Thought we'd give this place a try-- although we weren't sure if she would be able to sit on any of the rides. You have to be surprised by the size of this thing the moment you walk in-- since you are not prepared for that! We took a big walk around. Apart from a whole lot of arcade games scattered around, there are rides for all ages. We were able to find a few family rides other than a regular carousel that our daughter (standing exactly at 33 inches) could ride with us.
We did the BC Bus and Road runner a few times with her, and of course the Circus Carousel. She had a blast! Because we weren't sure while going in if we would be able to do many rides, we didn't buy a day pass. But this place is worth it only if you get one. We were there for barely an hour but paying for individual rides turned out a lot more expensive. There was also no consistency in the rules. When we bought the tickets, we were told that each of us would need a ticket to ride any of the rides (including the 2-year old). However, there were rides in which three of us sat with one ticket and rides in which three of us sat with three tickets.
One of the places in Vegas to kill hours with kids in Vegas. But make sure to get a day pass!