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