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