Just a quick idea for now...
For a twist on hide and seek, I hid some of Biscuit's toys in various pockets and compartments of one of our suitcases. Some I zipped shut, some I didn't. Biscuit liked opening the lid to find goodies inside...and closing it, and opening it, and closing it, and opening it, and climbing inside it!...all to his heart's content :D He also liked playing with the zippers and trying to work them himself. And when he was done searching for surprises, he loved scooting the luggage all over the house - it has wheels so naturally he thought it was a cool push toy :D