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