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