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