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