A product of corporate backer Southwest Airlines, the costume can only be unlocked one way - by playing a new level created by the airline itself!
“Southwest Air Adventure” can now be found in Super Mario Maker’s Event Courses. Completion of the level whilst wearing the “Sky Pop” costume will grant its access in other levels. To equip the costume in the first place, players will need to find a mystery mushroom somewhere in the level.
“Sky Pop” Mario is just one of twenty special costumes unlockable in Super Mario Maker through Event Courses. Additionally, there are over 100 costumes unlockable through challenges or Amiibo use.
It’s refreshing for a game to have corporate backers that provide gamers with visible content. The “Southwest Air Adventure” level is available to play now.