Here is the full list of all 41 Ratopia achievements.
Build a decorative structure.
Place a citizen in a group.
Experienced Spring's end.
Destroy infected's grave.
Rest on a Royal Bed
Activate a new policy.
Bury a dead to a grave.
Research a blueprint.
Assigne a ratizen to a job.
Accept a migrant.
Order soldeirs to escort.
Activate a shrine.
Build a rail in the city.
Find other cities.
Use a loan.
Make trade agreement.
Experienced Summer's end.
Experienced Autumn's end.
Experienced Winter's end.
Middle class appeared in the city.
Upper class appeared in the city.
Reach prosperity level 4
Reach prosperity level 7
Build a huge monument.
Keep at least 50 middle class for 12 days.
Keep at least 50 upper class for 12 days.
Survive a year in Hard difficulty.
Saves 99,999 Pia.
Build Merchant Monument.
Build Noble Monument.
Reach 100 population
Produce an equipment
Change the style of the leader
Enter the dungeon
Destroy Weasel Barracks
Supply electricity to the city for the first time.
Assemble a Ratron at the Ratron Assembly Plant
Conquering the Forgotten Mine
Conquering the Barbaric Palace
Build Scientist Monument
Operate more than 30 Ratrons