This barely counts as a prank - it's more just an insanely fun idea (assuming you own a house and have enough money to buy about 20,000 plastic balls to turn the first floor of your house into a ball pit). While a dad and his kids are at home, waiting for mom to get back, the dad decides - hey - why not make all of his childhood dreams come true and turn his home into a place that would make Chuck E. Cheese himself jealous?
The wife's reaction is fun 'n all, but - again - this mostly just looks like a ton of fun to put together.
Now excuse me, I need to go try to convince the bank to grant me a loan for...something that's not a giant ball pit. Definitely not to buy tens of thousands of plastic balls and a trampoline for an at-home ball pit though. Definitely not that. Ahem.