In some cases you may need real perpetual engine. But as you know engine like this does not exists. But these creative people made very funny and smart promo video where awesome split of cat and butter creates simple and very effective perpetual engine.
Plot are very simple: in one unnamed country very big problem with electricity and one of the heroes of the movie have to constantly turn the dynamo machine, the second is trying to make a sandwich but it falls to the bottom of the butter. This unexpected discovery leads him on an original idea.