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