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