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