What are the pros and cons of an indoor playground?

The reason why a few of my friends bring their children to indoor playgrounds is that the structures are designed to be safe for children. The playgrounds also allow their children to run around, climb up and down and expend much of their energy. The few of them usually arrange to go together for their children to play together while they get some time to “relax” and chitchat. The down side is that they are sometimes worried about the hygiene (got to do research well) and that it could be quite pricey. One of the places they prefer is Happy Willow (though it is quite small). They liked that the place also has a reading corner with books that parents can borrow to read to their children. http://www.happywillow.com.sg/