If you spent a lifetime of time, energy, and money crafting the perfect toy it would still not compare to the wonders of an empty cardboard box. We were lucky enough to get these giant matching boxes on one of our costco trips. When we first got them the kids played in them for a good hour. Popping in and out  like jack in the boxes. They took turns "crying" when the other went missing and delighting when they would reappear. We had to hang on to these boxes for a couple of days because the kids kept finding new uses for them. Props to the cardboar box!