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