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