Here is the full list of all 13 Prelude for a Dream achievements.
Got Orb of Aries
Got the Orb of Taurus
Got the Orb of Gemini
Got the Orb of Cancer
Got the Orb of Leo
Got the Orb of Virgo
Got the Orb of Libra
Got the Orb of Scorpio
Got the Orb of Sagittarius
Got the Orb of Capricorn
Got the Orb of Aquarius
Got the Orb of Pisces
Defeated Evil Satan