Here is the full list of all 12 Gnomes Garden: Lost King achievements worth 1,000 gamerscore.
For growing waterlillies
For exterminating Rats
For catching sheep
For restoring a ship
For activating an altar
For building a flying house
For collecting all trophies
For building the great portal
For speeding up workers
For catching a mound
For stopping time
For completing all levels with 3 stars