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