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.
Kill 100 Red Dudes with a rifle.
Kill 3 Red Dudes with one shotgun shot.
Kill 100 Red Dudes with a shotgun.
Kill 3 Red Dudes with one rifle burst.
Kill an enemy by jumping on him.
Kill 100 Red Dudes with a katana.
Complete the game.
Score 100 headshots.
Kill 100 Red Dudes with a pistol.
Get back to the system after being expelled.
Kill 100 Red Dudes using melee.
Cut bullet with a katana.
Complete SERV level.
Upload a replay on killstagram.com
Complete SUBWAY level.
Shoot down a bullet with a bullet.
Kill 2 Red Dudes with one katana throw.
Kill over 1987 Red Dudes in endless mode.
Unlock all endless levels.
Become part of the community.
Find all secrets.
Beat all Challenges.
Get RED ending in every level of SPEEDRUN challenge.
Get RED ending in every level of SPEEDRUNrt challenge.