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