Here is the full list of all 366 GooCubelets: OCD achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Beat Level 50
Beat Level 45
Beat Level 40
Beat Level 35
Beat Level 30
Beat Level 25
Beat Level 20
Beat Level 15
Beat Level 10
Beat Level 5
Finish level 1 more time
Beat Level 1