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