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
Release friend
Defeat the London Monitor
Locate the underwater stash
Solve the second Enigma code
Find the Laserkraftwerk
Solve the first Enigma code
Locate the resistance
Choose to save Fergus
Save allied planes
Choose to save Wyatt
Complete game on any difficulty
Complete game on I AM DEATH INCARNATE! (or ÜBER)
Complete game on ÜBER
Collect 25 gold items
Collect all gold items
Collect all letters
Solve the third Enigma code
Unlock stealth perk 1
Unlock stealth perk 2
Unlock stealth perk 3
Unlock stealth perk 4
Unlock stealth perk 5
Unlock stealth perk 6
Unlock stealth perk 7
Unlock stealth perk 8
Unlock tactical perk 1
Unlock tactical perk 2
Unlock tactical perk 3
Unlock tactical perk 4
Unlock tactical perk 5
Unlock tactical perk 6
Unlock tactical perk 7
Unlock tactical perk 8
Unlock assault perk 1
Unlock assault perk 2
Unlock assault perk 3
Unlock assault perk 4
Unlock assault perk 5
Unlock assault perk 6
Unlock assault perk 7
Unlock assault perk 8
Unlock demolition perk 1
Unlock demolition perk 2
Unlock demolition perk 3
Unlock demolition perk 4
Unlock demolition perk 5
Unlock demolition perk 6
Unlock demolition perk 7
Unlock demolition perk 8