Here is the full list of all 17 Cross Set achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Reveal Level 3.
Complete Level 1.
Reveal Level 2.
Solve one level.
Reveal Level 4.
Reveal Level 5.
Reveal Level 6.
Reveal Level 7.
Reveal Level 8.
Complete Level 2.
Complete Level 3.
Complete Level 4.
Complete Level 5.
Complete Level 6.
Complete Level 7.
Complete Level 8.
Clear every level.