There are 9 Trophies that can be collected.

Bronze

[ You're Halfway There ]
Complete half of either track list

[ There and Back ]
Have a particle go through a portal twice

[ Bouncy, Bouncy ]
Bounce a particle off the Deflect control 4 times

[ It's a Mess ]
Win by manually spraying particles into a container

[ Colors of the Wind ]
Have a single particle change its color 3 times

[ Lil' Big Steps ]
Beat the first act of any track list

Silver

[ Event Horizon ]
Beat a black hole level without ever losing a particle to a black hole

Gold

[ Maestro ]
Complete the Modern track list

[ Conductor ]
Complete the Classic track list

http://www.ps3trophies.org/game/auditorium-hd/trophies/