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