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