Here is the full list of all 12 Gnomes Garden: New Home achievements worth 1,000 gamerscore.
For restoring a plant
For constructing a building
For getting rid of a Gremlin
For speeding up workers
For stopping time
For speeding up construction
For completing all levels with 3 stars
For clearing one roadblock
For obtaining the Crystal of Eternal Light
For collecting all trophies
Collect 50 of every resource on a level
Collect 100 of any resource on a level