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