kids go into a dimention called upside down

When a young boy vanishes, a small town uncovers a mystery involving secret experiments, terrifying supernatural forces, and one strange little girl.

Oona, a recent graduate in anthropology, has returned to her dead mother’s seaside cottage in southern England to prepare it for sale. Her arrival disturbs Mani, a wary vagrant who has been squatting on the property.

When gravity is flipped for all children and their world turns upside down, the ceiling becomes the floor and the floor becomes the ceiling!

Adults are so fed up with disobedient children, they left them and went off camping. All of them. First, the children were happy - now you can do anything, no washing, dance all night and no school! But then they run out of food, nothing to eat, cook for the children themselves can not and do not know how, and there's no one to treat them when the stomach aches or headache, or when you fall off your bike. At the end the kids decide to send a kite to the parents, with a request to forgive them.

Children play. First shown normally, then shown in reverse.