Here is the full list of all 36 Firmament Wars achievements.
Established a new nation
Destroyed a fortress with a nuclear weapon
Added two comrades to your friend list
Updated your national flag
Updated your nation's name
Won 10 ranked games
Won 10 team games
Won 10 FFA games
Achieved 1800+ rating
Achieved 2100+ rating
Achieved 2400+ rating
Achieved 2700+ rating
Great Revolutionary conquered a tile with 100+ units
Win a game with a 2:1 kill ratio
Won 10 games in a row
Won 25 games in a row
Conquered a tile with a fortress
Won a game under Despotism
Won a game as a Monarchy
Won a game as a Democracy
Won a game under Fundamentalism
Won a game under Fascism
Won a game as a Republic
Won a game under Communism
Won 500 FFA games
Won 500 ranked games
Won 500 team games
Hit top #10 on the ranked leaderboard
Hit top #100 on the ranked leaderboard
Hit top #1000 on the ranked leaderboard
Defeated the Juggernaut
Win an 8-player FFA game
Won 100 FFA games
Won 100 ranked games
Won 100 team games
Build a fortress