Here is the full list of all 26 SUPERHOT achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Get back to the system after being expelled.
Kill 100 Red Dudes with a katana.
Launch every app in the system.
Complete the game.
Score 100 headshots.
Kill 100 Red Dudes with a shotgun.
Kill 100 Red Dudes using melee.
Kill 3 Red Dudes with one rifle burst.
Kill 100 Red Dudes with a pistol.
Kill 2 Red Dudes with one katana throw.
Cut bullet with a katana.
Upload a replay on killstagram.com
Become part of the community.
Complete SERV level.
Kill an enemy by jumping on him.
Shoot down a bullet with a bullet.
Complete SUBWAY level.
Kill 100 Red Dudes with a rifle.
Kill over 1987 Red Dudes in endless mode.
Kill 3 Red Dudes with one shotgun shot.
Unlock all endless levels.
Find all secrets.
Beat all Challenges.
Get RED ending in every level of SPEEDRUN challenge.
Get RED ending in every level of SPEEDRUNrt challenge.