Phineas and Ferb: Quest for Cool Stuff walkthrough part 12 (final part). This includes the last level of the game 'Last Side of the Moon' and the ending credits. Phineas and Ferb are on a mission to spend the last week of their summer vacation collecting the coolest stuff in the world for their own museum. Phineas and Ferb construct their newest invention, the All-Terrain Transformatron (A.T.T.) and head off to the Temple of Cool in search of treasures.