Logically Pokemon World is a game inspired by the popular Japanese series, whose objective is to go along the different levels hunting for all the pokemons you can find (150 in total) and thus convert yourself into the best pokemon hunter in the world.
You can locate the different characters in such diverse places as in water, hidden in caves or hiding in long grass, with the added difficulty that each one can have different shapes and sizes (and personality and behaviour). Some look like plants, others animals, and so as they mimic their environment they`re more difficult to find.
If you manage to capture all the species of pokemon there are, then you can be considered the total untraceable pokemon hunter.