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