Here is the full list of all 42 Gunpoint achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Notice the story doesn't necessarily gel with the mechanics. Become qualified games journalist.
Create a custom mission with at least one objective.
Free an innocent man at the expense of catching a guilty one.
Tell Gessler that Rooke's hired you to betray him.
Chicken out of telling Katie the truth at the last minute.
Voluntarily tell Katie the truth.
Mock the chief of police at a critical moment.
Kick Fritz Gessler's office door into him.
Use the Prankspasm to knock out someone who isn't standing near a power socket (outside of the test lab).
Beat Fritz Gessler to death.
Complete a mission faster than I can.
Slam Fritz Gessler's office door into him.
Intimidate Fritz Gessler into surrendering.
Knock Fritz Gessler out of his office window.
Knock Fritz Gessler out with a punch.
Jump into an Enforcer to knock him through a window.
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.
Upgrade your battery capacity to the non-figurative max.
Upgrade your Bullfrog Hypertrousers to pounce instantly.
Publish your personalised epilogue.
Complete the game.
Shoot Fritz Gessler.
Help justify my early, not entirely wise choice of game name by holding someone at gunpoint with the Resolver.
Defeat Gessler by rewiring his gun.
Catch a guilty man at the expense of freeing an innocent one.
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.
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.
Upgrade your Bullfrog Hypertrousers to maximum jump strength.
Use the Hushcracker to jump through a window silently (outside of the test lab).
This is an achievement in name only. No-one admires you for punching a guy that many times.
Wire an elevator button to trigger something when the elevator arrives.
Leave no living witnesses to your presence on a mission that has guards.
Use no violence at all on a mission that has guards.
Complete a mission that has guards with no violence, witnesses or loud noises.
Use the Crosslink to create an infinite loop that burns itself out.
Knock a guard out by opening a door into him.
Get knocked down by an opening door.