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