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.
Knock Fritz Gessler out of his office window.
Defeat Gessler by rewiring his gun.
Beat Fritz Gessler to death.
Knock Fritz Gessler out with a punch.
Intimidate Fritz Gessler into surrendering.
Notice the story doesn't necessarily gel with the mechanics. Become qualified games journalist.
Kick Fritz Gessler's office door into him.
Chicken out of telling Katie the truth at the last minute.
Voluntarily tell Katie the truth.
Tell Gessler that Rooke's hired you to betray him.
Use the Prankspasm to knock out someone who isn't standing near a power socket (outside of the test lab).
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.
Complete a mission that has guards with no violence, witnesses or loud noises.
Free an innocent man at the expense of catching a guilty one.
Jump into an Enforcer to knock him through a window.
Mock the chief of police at a critical moment.
Publish your personalised epilogue.
Complete the game.
Shoot Fritz Gessler.
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.
Complete the police chief's missions without incriminating yourself.
Conceal your presence at the DataSec break-in from Mayfield.
Use the Dropshot to land silently from a great height.
Help justify my early, not entirely wise choice of game name by holding someone at gunpoint with the Resolver.
Steal Gessler's technology for Rooke.
Knock a guard out by opening a door into him.
Upgrade your battery capacity to the non-figurative max.
Use the Hushcracker to jump through a window silently (outside of the test lab).
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.
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.
Use the Crosslink to create an infinite loop that burns itself out.