Here is the full list of all 55 TerraScape achievements.
Unlock the Terra Colossal Crater
Unlock the Science Deck
Unlock the Terra Vexing Valley
Unlock the Terra Bonny Basin
Unlock the Beverages Deck
Unlock the Terra Massive Massif
Achieve a Gold Medal on any Free Play/Scenario Terra by only scoring at least a gold-rating with every building placed.
Finish 1 Multiplayer Session
Start 1 Multiplayer Session
Earn 30 Puzzle Terra Gold Medal
Unlock the Iron Industry Deck
Unlock the Terra Soaring Summits
Unlock the Terra Challenge Continent
Unlock the Terra Advanced Atoll
Unlock the Terra Harmonic Hills
Earn 30 Challenge Level Bronze Medals
Earn 1 Puzzle Terra Gold Medal
Earn 5 Puzzle Terra Gold Medal
Earn 15 Puzzle Terra Gold Medal
Unlock the Terra Epic Expanse
Unlock the Terra Peerless Plateau
Unlock the Terra Idyllic Island
Earn 15 Challenge Level Bronze Medals
Earn 5 Challenge Level Bronze Medals
Reach the Bronze Medal in any Challenge Level
Merge 1 Longhouse
Merge 1 City District
Reach Keep Level 5
Unlock the Mining Deck
Unlock the City Deck
Unlock the Farming Deck
Unlock the Fishing Deck
Unlock the Village Deck
Place your Keep
Open the Multiplayer Screen
Merge 1 Cathedral
Start 5 Multiplayer Sessions
Start 15 Multiplayer Sessions
Finish 5 Multiplayer Sessions
Finish 15 Multiplayer Sessions
Earn 45 Puzzle Terra Bronze Medals
Earn 45 Puzzle Terra Gold Medal
Place 50 buildings in creative Mode