Here is the full list of all 42 Gunpoint achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Create a custom mission with at least one objective.
Slam Fritz Gessler's office door into him.
Knock Fritz Gessler out of his office window.
Chicken out of telling Katie the truth at the last minute.
Tell Gessler that Rooke's hired you to betray him.
Intimidate Fritz Gessler into surrendering.
Shoot Fritz Gessler.
Beat Fritz Gessler to death.
Jump into an Enforcer to knock him through a window.
Mock the chief of police at a critical moment.
Use the Hushcracker to jump through a window silently (outside of the test lab).
This is an achievement in name only. No-one admires you for punching a guy that many times.
Complete a mission faster than I can.
Knock Fritz Gessler out with a punch.
Defeat Gessler by rewiring his gun.
Use the Longshot to make a guard unintentionally shoot another (outside of the test lab).
Help justify my early, not entirely wise choice of game name by holding someone at gunpoint with the Resolver.
Free an innocent man at the expense of catching a guilty one.
Voluntarily tell Katie the truth.
Publish your personalised epilogue.
Notice the story doesn't necessarily gel with the mechanics. Become qualified games journalist.
Complete the game.
Kick Fritz Gessler's office door into him.
Catch a guilty man at the expense of freeing an innocent one.
Use the Gatecrashers to kick a door through a window.
Use the Gatecrashers to kick a door into a guard.
Use the Gatecrashers to kick a door off its hinges.
Steal Gessler's technology for Rooke.
Use the Prankspasm to knock out someone who isn't standing near a power socket (outside of the test lab).
Get knocked down by an opening door.
Complete the police chief's missions without incriminating yourself.
Use the Crosslink to create an infinite loop that burns itself out.
Upgrade your battery capacity to the non-figurative max.
Upgrade your Bullfrog Hypertrousers to maximum jump strength.
Conceal your presence at the DataSec break-in from Mayfield.
Complete a mission that has guards with no violence, witnesses or loud noises.
Use the Dropshot to land silently from a great height.
Wire an elevator button to trigger something when the elevator arrives.
Use no violence at all on a mission that has guards.
Leave no living witnesses to your presence on a mission that has guards.
Knock a guard out by opening a door into him.
Upgrade your Bullfrog Hypertrousers to pounce instantly.