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