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