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