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.
Clear every level.
Complete Level 7.
Complete Level 8.
Reveal Level 8.
Complete Level 6.
Reveal Level 7.
Complete Level 5.
Reveal Level 6.
Complete Level 4.
Reveal Level 5.
Complete Level 3.
Reveal Level 4.
Complete Level 2.
Reveal Level 3.
Complete Level 1.
Reveal Level 2.
Solve one level.