When you are in the gummie ship to make sure that you have completed a world look at the ring around the world and if its glieery or shiny or glitter is comming up from it or if its bright that means you beat the world but if its not go back and land on that world to complete it, when u complete a world it should say the name of that world like it did when you first landed there for instance if i finish everything in atlantica i would know because it would say atlantica at the end as if its a ending of a movie.