Here is the full list of all 20 Cliff Empire achievements.
Survive 20 waves of Marauders
The moment when two warehouses arrive at once
Critically low ecology
Fully load trading barge
The explosion of the nuclear power plant
Get up by elevator of entertainment center
Reach 7000 population on Earth
Fly by personal transport when all your cities have a 1000000¢ in total
Defrost 2000 people
Complete 100% of all researches
More agrarian drones count than ordinary
Reach 200 newborn on Earth
Complete 50% of all researches
Earn 50000¢
Complete 25% of all researches
Destroy 10 buildings in a row
Save 20 buildings from fire
Build 10 buildings at once