Here is the full list of all 13 Milky Way Prince – The Vampire Star achievements.
Avoid Critical Collapse
All Endings Completed
Ask the tough questions
Try all the offerings at the Moonage Daydream
Find Anita
Refuse to play his game
Wear perfume and see what happens
Save the Milky Way Prince
See the world through his eyes
Find a way to distract him from his thoughts
Pay attention to your companion
Keep an eye on the changes in your room
Shave and see what happens