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