Builder's Journey Achievement in LEGO Builder's Journey
Complete the Journey
How to unlock Builder's JourneyStory-related; cannot be missed.
This achievement will unlock after the credits. The final level is the same one you complete for Together (75G), in terms of replay. Note that you must also wait for the flying machine to take you all the way back to your house, at the end of the credits, for this achievement to unlock.
The following video, courtesy of Cheevo Guides, shows a full game walkthrough with possible solutions for all of the levels.