This is a fantastic toy! Our kids, age 3 to 6 play with it regularly and for hours at a time. The negotiation and planning that goes into the building is great to watch. Building and then rebuilding seems to be the most fun. I can see now where my kids are actually learning what works and what doesn't. They spent a lot of time building structures that fell down easily, only to return with a 'new idea'. Then build another structure and test their idea. The balls allow you to build in almost any direction. Now they build structures that support two flannel blankets. This is so much better than how our living room furniture used to be moved around and blankets thrown over them for a fort. Even those furniture forts never worked at first and needed to be adjusted, and they couldn't move the furniture themselves...Crazy Forts is a great toy and I am sure my kids are learning while playing!