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