Here is the full list of all 26 SUPERHOT achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Find all secrets.
Beat all Challenges.
Kill over 1987 Red Dudes in endless mode.
Get RED ending in every level of SPEEDRUN challenge.
Get RED ending in every level of SPEEDRUNrt challenge.
Unlock all endless levels.
Kill 3 Red Dudes with one rifle burst.
Kill 2 Red Dudes with one katana throw.
Launch every app in the system.
Upload a replay on killstagram.com
Become part of the community.
Kill 100 Red Dudes with a rifle.
Kill 100 Red Dudes with a shotgun.
Kill 100 Red Dudes with a katana.
Cut bullet with a katana.
Complete the game.
Kill 3 Red Dudes with one shotgun shot.
Get back to the system after being expelled.
Kill 100 Red Dudes using melee.
Kill an enemy by jumping on him.
Kill 100 Red Dudes with a pistol.
Score 100 headshots.
Complete SERV level.
Shoot down a bullet with a bullet.
Complete SUBWAY level.