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