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