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