Here is the full list of all 42 Gunpoint achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Slam Fritz Gessler's office door into him.
Knock Fritz Gessler out of his office window.
Defeat Gessler by rewiring his gun.
Shoot Fritz Gessler.
Intimidate Fritz Gessler into surrendering.
Voluntarily tell Katie the truth.
Mock the chief of police at a critical moment.
Create a custom mission with at least one objective.
Use the Prankspasm to knock out someone who isn't standing near a power socket (outside of the test lab).
Use the Longshot to make a guard unintentionally shoot another (outside of the test lab).
Upgrade your battery capacity to the non-figurative max.
Complete a mission faster than I can.
Notice the story doesn't necessarily gel with the mechanics. Become qualified games journalist.
Kick Fritz Gessler's office door into him.
Help justify my early, not entirely wise choice of game name by holding someone at gunpoint with the Resolver.
Use the Gatecrashers to kick a door through a window.
Use the Gatecrashers to kick a door into a guard.
Free an innocent man at the expense of catching a guilty one.
This is an achievement in name only. No-one admires you for punching a guy that many times.
Tell Gessler that Rooke's hired you to betray him.
Wire an elevator button to trigger something when the elevator arrives.
Publish your personalised epilogue.
Complete the game.
Beat Fritz Gessler to death.
Knock Fritz Gessler out with a punch.
Catch a guilty man at the expense of freeing an innocent one.
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.
Get knocked down by an opening door.
Steal Gessler's technology for Rooke.
Complete a mission that has guards with no violence, witnesses or loud noises.
Use no violence at all on a mission that has guards.
Use the Hushcracker to jump through a window silently (outside of the test lab).
Chicken out of telling Katie the truth at the last minute.
Use the Dropshot to land silently from a great height.
Upgrade your Bullfrog Hypertrousers to pounce instantly.
Jump into an Enforcer to knock him through a window.
Knock a guard out by opening a door into him.
Use the Crosslink to create an infinite loop that burns itself out.
Leave no living witnesses to your presence on a mission that has guards.