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