Here is the full list of all 15 Disney Infinity 3.0 Edition (Windows) achievements worth 1,000 gamerscore.
Complete 25 Feats
Feed a Sidekick 50 times
Complete all Toy Box and INterior tutorials
Earn 10 Toy Presents in the Toy Box Hub
Harvest 100 plants
Build a 20-room INterior
Throw a party for your friends in one of the designated Sidekick Rooms
Earn 5 Sidekicks
Complete 5 Feats
Reveal all the terrain in the Toy Box Hub
Play a downloaded UGC in the theater (Xbox Live, Single Player Only)
Save a Toy Box
Play all Toy Box Adventures
Complete 75 Feats
Complete 50 Feats