There are 26 Trophies that can be collected.

Bronze

INKT informed
Pinky's Guide to inkies completed

Pinky to the rescue
Blob and Pinky played a level together

Keepin' it real
All levels completed without upgrades

Silver

Paradise Island liberated
'Paradise Island' level completed

Maximum Blob
Blob and Pinky completely upgraded

Every picture
Every Gallery pickup collected

Totally inspired
Every inspiration pickup collected or earned

Gold

INKT smasher
All Gold Clean-Up awards completed

The People's Hero
All Gold Liberation awards completed

Nature Lover
All Gold Environment awards completed

Nothing but the best
All story levels completed to 'S' class

Medal of Color
All story levels completed in normal mode

Platinum

Platinum Trophy
All Trophies obtained!

12 Secret

http://www.ps3trophies.com/forums/showthread.php?t=55176