Here is the full list of all 22 InfiniPicross achievements.
Use The Workshop
5 Solved
Reset a Filled Grid
Set a Seed
Create a Theme
One Continue
15x15 or Bigger Completed
25x25 or Bigger Completed
Change Theme
First Solve
3x3 or Bigger Completed
5x5 or Bigger Completed
10x10 or Bigger Completed
10 Solved
25 Solved
50 Solved
100 Solved
50x50 or Bigger Completed
99x50 (or 50x99) or Bigger Completed
5 Continues in a Row
10 Continues in a Row
A Certain Familiarity