Here is the full list of all 50 Wolfenstein: The New Order achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Solve the fourth Enigma code
Complete game on ÜBER
Defeat the London Monitor
Release friend
Complete game on any difficulty
Complete game on I AM DEATH INCARNATE! (or ÜBER)
Collect all letters
Solve the second Enigma code
Solve the third Enigma code
Unlock demolition perk 8
Unlock assault perk 5
Unlock demolition perk 3
Solve the first Enigma code
Unlock assault perk 4
Unlock assault perk 8
Unlock assault perk 7
Unlock demolition perk 2
Unlock tactical perk 8
Unlock tactical perk 7
Locate the underwater stash
Unlock tactical perk 5
Unlock tactical perk 6
Collect 25 gold items
Unlock assault perk 6
Find the Laserkraftwerk
Unlock assault perk 3
Locate the resistance
Unlock assault perk 2
Unlock stealth perk 8
Unlock assault perk 1
Unlock stealth perk 4
Unlock stealth perk 6
Choose to save Fergus
Unlock tactical perk 2
Unlock tactical perk 4
Unlock tactical perk 3
Unlock stealth perk 5
Unlock tactical perk 1
Unlock stealth perk 7
Unlock stealth perk 3
Unlock stealth perk 2
Unlock stealth perk 1
Unlock demolition perk 1
Save allied planes
Choose to save Wyatt
Collect all gold items
Unlock demolition perk 4
Unlock demolition perk 5
Unlock demolition perk 6
Unlock demolition perk 7