We had a 6 hour layover in Phoenix with 2 kids and found this place. It is accessible by light rail so we did not need car seats to get our kids here. They normally close at 4pm, but were open from 5-9pm on this Friday because it was the first Friday of the month. We got there right at 5pm and thankfully so because when we left at 6:15 or so, there was a line around the building (since it was a free admission night).
The staff are extremely friendly and the facilities are top notch. There are different areas encouraging both sciences and pretend play. There is a special "shoe-free" toddler area which was great because the bigger kids are not allowed in there. My 3 year old liked the grocery store and kitchen rooms and also the noodle area that you can walk through. I wish we had this in Dallas!