Here is the full list of all 50 Wolfenstein: The Old Blood achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Complete game on any difficulty
Complete game on I AM DEATH INCARNATE! (or ÜBER)
Complete the nightmare boss level
Unlock the Grenade belt perk
Collect 32 gold items
Choose to save Kessler
Unlock the Schockhammer clip upgrade perk
Complete the nightmare in chapter 6
Unlock the Reload mash perk
Collect 5 letters
Unlock the Ammunition upgrade perk
Complete the nightmare in chapter 5
Complete part one
Unlock the Health upgrade III perk
Unlock the Health upgrade II perk
Complete the nightmare in chapter 4
Collect 16 gold items
Unlock the Bombenschuss clip upgrade perk
Escape Castle Wolfenstein
Unlock the Armor upgrade I perk
Unlock the Quick turn perk
Complete the nightmare in chapter 3
Collect 8 gold items
Unlock the Health upgrade I perk
Infiltrate Castle Wolfenstein
Choose to save Annette
Complete game on ÜBER
Complete all nightmare levels
Complete the prologue nightmare
Complete the nightmare in chapter 1
Complete the nightmare in chapter 2
Complete the nightmare in chapter 7
Achieve gold medal for this challenge map
Collect all letters
Collect 64 gold items
Unlock the Eagle Eye perk
Unlock the Armor upgrade II perk
Unlock the Vampire perk
Unlock the Kampfpistole ammo storage upgrade perk
Unlock the Carry heavy machinegun perk
Unlock the Tough Skin perk