As you play through the game, there are collectibles that you can collect and each of them shows emails and other information that further expands the story of the game. (justpushstart.com)
It will include much of the same content, including new, expanded story with more levels and quests. (nintendotoday.com)
I plan to expand the story into an ongoing series of stories, but for now, you can join the adventure and subscribe to read the first story here. (elasticmind.ca)