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