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