Here is the full list of all 38 Cities: Skylines II achievements.
Have a total of 10,000 tourist visits in a single city.
Have at least 1000 citizens and a city attractiveness rating of 90.
Bulldoze a total of 1000 buildings.
Have 20 active transport lines. These can be passenger or cargo lines or any mix of the two.
Reach a population of 100,000.
Have 6,000 citizens treated at medical clinics or hospitals in a single city.
Create a city district and assign a city service to that district.
Unlock 50 map tiles in a single city.
Plant 100 trees or bushes with the landscaping tool in a single city.
Build any airport.
Assign a policy to a city district.
Use the photo mode to take a screenshot.
Experience all four seasons by building a city in a climate with a snowy winter.
Build 5 signature buildings in a single city.
Have a total loan of at least 200,000 in a single city.
Have a look at each individual info view panel.
Experience a hailstorm.
Experience a tornado.
Reach enough milestones to unlock all city services in a single city.
Build 10 parks in a single city.
Have at least 1000 citizens and an average happiness rating of 75%.
Experience a forest fire.
Have buildings from all four zone types in a single city.
Build city with residential, commercial and industrial zones, water, and electricity.
Unlock each building available in the base game.
Have a city that produces electricity by only using renewable energy sources.
Unlock 150 map tiles in a single city.
Have 5 city policies active simultaneously.
Create 10 different districts in a single city and assign policies to each.
Follow a citizen's lifepath from childhood to old age.
Use the editor to make a map.
Reach milestone 20.
Have 50 active transport lines. These can be passenger or cargo lines or any mix of the two.
Have at least 1000 citizens and an average happiness rating of 25%.
Build 10 signature buildings in a single city.
Use the editor to make an asset of any other type than map.
Build a city where at least 20% of the population has a university level of education.
Build all unique city service buildings in a single city.