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