Earn three stars in all five locations in North of Never Land.
This achievement requires that you earn three stars on each location in the episode. One star is earned just for completing the level. Another one is earned for collecting all of the Lost Things. The final star is earned for finding/cleaning all of the gold doubloons on the level.
The Lost Things are generally human-sized items which look out of place and are usually found in the Hidden Areas (spider holes), but they can be found outside in the scene on occasion. The gold doubloons are only found in the main scene (not in the Hidden Areas) and must be tapped on and brushed cleaned to count as collected. These items are always located in the same position, so feel free to use the walkthrough located in the story-related achievements of the guide for the exact location if you cannot find something.
Make sure you collect these before completing the level. In order to get them to save as collected, you will have to play though the entire level again. If you have been collecting all these items throughout, this achievement will pop at the end of the balloon scene of the last level. The stars you have earned on each level can be seen from the level-selection map.