Here is the full list of all 21 Humans Must Answer achievements.
Pass border patrol
Take the Chicken's Way Out
Kill The Starbound Penguin
Obtain the support weapon
Upgrade any weapon to max level
Collect 10% of the golden eggs
Collect 25% of the golden eggs
Collect 50% of the golden eggs
Collect 75% of the golden eggs
Collect 100% of the golden eggs
Defeat Sheriff Gilgamesh
Defeat DNA
Defeat The Martian Drill Laser
Defeat The Ankh
Beat 1 level to 100% (Gold status)
Beat 5 levels to 100% (Gold status)
Beat 10 levels to 100% (Gold status)
Beat 15 levels to 100% (Gold status)
Beat 20 levels to 100% (Gold status)
Die as a hero, live as a villain
When you do things right, people won't be sure you've done anything at all