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