Here is the full list of all 50 Citizens of Earth achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Get all citizens to Lv 30.
Receive 10,000 damage in combat.
Use 150 items.
Recruit all 40 citizens.
Defeat the Secretary Supreme.
Defeat the Alien Commander.
Defeat the Mishmasher.
Earn $100,000 in the Casino.
Defeat Honcho Villa.
Complete all Photography quests.
Defeat Agent D.O.O.M.
Defeat DJ Voodoo.
Complete all Extermination quests.
Complete all Wanted Poster quests.
Defeat the Hippie Guru.
Use 75 items.
Defeat the Puppet President.
Receive 2,500 damage in combat.
Ambush 10 enemies in a row.
Defeat Colonel Cookie.
Use 25 items.
Recruit 25 citizens.
Collect 300 items.
Enroll 9 citizens simultaneously in School.
Defeat 1,000 enemies.
Find 100 treasures.
Spend $10,000.
Earn $10,000.
Deal 10,000 damage in combat.
Defeat 250 enemies.
Get one citizen to Lv 20.
Spend $3,000.
Spend $1,000.
Get one citizen to Talent Lv 3.
Collect 100 items.
Discover 30 locations.
Find 45 treasures.
Receive 500 damage in combat.
Discover 20 locations.
Defeat Mr. Mocha.
Earn $3,000.
Deal 2,500 damage in combat.
Find 15 treasures.
Recruit 5 citizens.
Earn $1,000.
Discover 10 locations.
Defeat the Opposition Leader.
Defeat 50 enemies.
Deal 500 damage in combat.
Collect 30 items.