Here is the full list of all 23 de Blob achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Paint everything... e-ve-ry-thing!
Master De Blob in all possible ways
Earn 30 gold medals.
Run to defeat the time.
What a style!
Decorate all trees.
Prepare the billboard.
They may take away our colour, but they'll never take our freedom!
To blimp and beyond!
Defeat'em all.
Shake! Shake! Shake!
Get all gold medals in story mode.
Optimus paint engine.
Defeat INKT Corporation.
Save Ministry of Ink from INKT Corporation.
Save Chroma City Fun Park from INKT Corporation.
Save Hanging Gardens from INKT Corporation.
Save the Docklands from INKT Corporation.
Save Guggentraz Island from INKT Corporation.
Save the Chroma Dam from INKT Corporation.
Save Downtown from INKT Corporation.
Save Uptown from INKT Corporation.
Save Last Resort from INKT Corporation.