Here is the full list of all 7 Travel Mosaics 10: Spooky Halloween achievements.
Solve all 20 additional puzzles.
Complete all the main levels in the first 16 locations while earning 3 stars in each level.
Complete all 20 bonus levels while earning 3 stars.
Complete all the main levels in all locations while earning 3 stars in each level.
Complete all the main levels in the first 12 locations while earning 3 stars in each level.
Complete all the main levels in the first 8 locations while earning 3 stars in each level.
Complete all the main levels in the first 4 locations while earning 3 stars in each level.