Here is the full list of all 11 Cross Pixels achievements.
Solve your first Level
Complete 10 Levels
Solve 50 Levels
Complete 150 Levels
Solve 250 Levels
Complete everything! Now go on and solve some more Workshop Levels
Tiny Levels are no longer a challenge for you
10x10 what a joke! You need bigger challenges
Come on give me more...
Now we are talking
The tools are yours, now go and use them.