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