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