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