Here is the full list of all 20 Idol Hands achievements.
Create 5 volcanoes in a single level
Kill 200 enemy furlings
Throw 5 meteors in a single level
Complete all tutorials
Complete level 5 onwards with only 6 farmers
Complete level 5 onwards with only 5 woodcutters
Your priest converts his first enemy furling
Throw 20 lightning bolts in a single level
Make it rain 20 times in a single level
Trigger 10 earthquakes in a single level
Complete a level without losing one of your furlings
Create your first army of 10 soldiers
Create your first priest
Expose your first iron ore
Finish "In the Beginning...", the first tutorial level
Play the game for the first time
Your priests have converted 20 enemy soldiers
Game completed by winning the final level
Collect 10,000 units of wood
Destroy 10 buildings with volcanoes