Here is the full list of all 25 de Blob 2 achievements.
Every Gallery pickup collected
All levels completed without upgrades
Blob and Pinky completely upgraded
Every Inspiration pickup collected or earned
All story levels completed to "S" class
All Gold Clean-up awards completed
All Gold Liberation awards completed
All Gold Environment awards completed
Blob and Pinky played a level together
"Hypno Ray" level completed
Pinky's Guide to Inkies completed
All story levels completed in normal mode
"Rocket Range" level completed
"Inky Fabricator" level completed
"Prison Zoo" level completed
"Blanc TV Factory" level completed
"Inktron Collider" level completed
"Blanc Cola Cannery" level completed
"Comrade Black U." level completed
Completed 10 continuous piston jumps
"The Senate" level completed
"Blanctown" level completed
"Downtown" level completed
"Paradise Island" level completed
Completed a level in a single playthrough without dying