Here is the full list of all 15 Disney Infinity 3.0: Play Without Limits achievements.
Reveal all the terrain in the Toy Box Hub
Throw a party for your friends in one of the designated Sidekick Rooms
Play all Toy Box Adventures
Complete 75 Feats
Feed Sidekick 50 times
Harvest 100 plants
Complete 50 Feats
Build a 20-room INterior
Earn 10 Toy Presents in the Toy Box Hub
Play a downloaded UGC in the theater (Steam, Single Player Only)
Save a Toy Box
Complete 25 Feats
Earn 5 Sidekicks
Complete 5 Feats
Complete all Toy Box and INterior tutorials