Full list of all 66 Ready or Not achievements. It takes around 0-1 hour to unlock all of the achievements in the base game on Windows.
The base game contains 15 achievements, and there are 4 DLC packs containing 51 achievements.
Complete ‘Dorms’ at C+ on 'Standard' difficulty or higher
Complete ‘Lawmaker’ at C+ on 'Standard' difficulty or higher
Complete ‘Narcos’ at C+ on 'Standard' difficulty or higher
Complete ‘Narcos’ using only lethal pistols but without using grenades or launchers on 'Standard' difficulty or higher
Restrain all civilians in ‘Lawmaker’ without neutralizing any suspects on 'Standard' difficulty or higher
Complete all Home Invasion levels at S on 'Standard' difficulty or higher
Complete all ‘Dorms’ main objectives in five minutes on 'Standard' difficulty or higher
Get all Ready Or Not Home Invasion DLC achievements
Complete ‘Mirage at Sea’ at C+ on 'Standard' difficulty or higher
Complete ‘Leviathan’ at C+ on 'Standard' difficulty or higher
Complete ‘3 Letter Triad’ at C+ on 'Standard' difficulty or higher
Complete all Dark Waters levels at S on 'Standard' difficulty or higher
During ‘Mirage at Sea’, apprehend Sah’id before the order is given to murder civilians, and no civilians are killed on 'Standard' difficulty or higher
During ‘Leviathan’, successfully hit two long-range headshots, on two different active Suspects, located over 30m away from you on 'Standard' difficulty or higher
During ‘3 Letter Triad’, apprehend or incapacitate 15 suspects consecutively, within 15 seconds of one another on 'Standard' difficulty or higher
Get all Ready Or Not Dark Waters DLC achievements
Complete all base game missions on 'Hard' difficulty in any game mode
Unlock each unique officer trait at least once
Complete 'Training'
Unlock all base game customization items
Drink one too many coffees
Complete 'Twisted Nerve' using only VPL-25, cs gas, gasmasks, and bash on 'Standard' difficulty or higher
Complete ‘Thank You, Come Again’ without armor and a helmet on 'Standard' difficulty or higher
On 'A Lethal Obsession' play all of the audiotapes that can be found in the mission
Command your squad to breach a door, 20 times
Command your squad to breach a door, 50 times
Arrest 50 suspects or civilians
Arrest 100 suspects or civilians
Inspect any evidence item from the 'Evidence locker' in the 'Headquarters'
Disarm 10 tripwires
Breach 20 locked doors with the 'Battering Ram'
Use the 'Mirrorgun' 30 times under a door
Stun enemies with any 'M320' 30 times
Unlock 20 doors using the 'Lockpick Gun'
Have 2 officers with an active “Kicker” trait assigned to the roster and kick a door open in any mission
Complete a mission without using a weapon and only relying on deployables, tactical gear, and bash on 'Standard' difficulty or higher
Complete a mission while only commanding your officers and not using anything from your loadout on 'Standard' difficulty or higher
Complete ‘No Good Deed’ at C+ on 'Standard' difficulty or higher
Complete ‘All Gods Burn’ at C+ on 'Standard' difficulty or higher
Complete ‘A New America’ at C+ on 'Standard' difficulty or higher
Complete all Boiling Point levels at S on 'Standard' difficulty or higher
During any Boiling Point mission, while you are actively taking damage from toxic gas, incapacitate three different active Suspects within 5 seconds of one another on ‘Standard’ or higher.
Complete ‘All Gods Burn’ without Armor or a Shield equipped and without using grenades, on ‘Hard’ difficulty.
Complete ‘A New America’, alone in a multiplayer lobby, on ‘Hard’ difficulty.
Find and use all major world interactables in every Boiling Point level.