The idea of Tasty Planet is simple. You control a tiny ball of grey goo which eats everything around it.
It was created as a bathroom cleaner. The grey goo was only supposed to eat dirt and bacteria - cleaning your bathroom automatically. Instead it eats everything: dirt, bacteria, bugs, fish, mice, cats, dogs, cars, trees, houses... Everything! Soon the entire planet will be eaten by this crazy ball of goo. Fortunately you're on the goo side.