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