The 'Basic 3x3' board:
The board selection window. You can pull up a category by difficulty level or board size. As each board is selected, a preview appears to the side:
An 'Advanced' board (fewer controls) in 'Difficult' mode. In this mode, both layers are purple. You can only determine which is which by moving them:
An 'Expert' board (sparse controls) in 'Impossible' mode. In this mode, both layers are purple AND overlaps are hidden. It is much harder to determine which layer is which:
