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