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