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