Here is the full list of all 14 DUSK '82: ULTIMATE EDITION achievements. It takes around 1-2 hours to unlock all of the achievements on Windows.
Upload a custom level to the workshop
Create and test a level where you kill 10 enemies and exit in 3 or less moves
Destroy every tree in the first level before finishing it
Finish the entire game
Defeat the final boss
Finish level 25
Find The Soap
Kill 5 enemies with a single crossbow bolt
Kill an enemy by pushing a barrel down a conveyer belt
Kil 3 enemies with a single explosion
Get crushed by a toggle wall
Finish any level with 2500 points or more
Kill yourself with an explosion
Finish any level