Here is the full list of all 25 de Blob 2 achievements.
All levels completed without upgrades
Completed 10 continuous piston jumps
Blob and Pinky completely upgraded
Every Gallery pickup collected
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
Pinky's Guide to Inkies completed
All story levels completed in normal mode
"Hypno Ray" level completed
"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
"The Senate" level completed
"Blanctown" level completed
"Downtown" level completed
Completed a level in a single playthrough without dying
Blob and Pinky played a level together
"Paradise Island" level completed