ascending order.
In basic Twiddle, your move is to rotate a square group of four
-tiles about their common centre. (Orientation is not significant:
-tiles never end up upside down!) On more advanced settings, you can
-rotate a larger square group of tiles.
+tiles about their common centre. (Orientation is not significant in
+the basic puzzle, although you can select it.) On more advanced
+settings, you can rotate a larger square group of tiles.
I first saw this type of puzzle in the GameCube game \q{Metroid
Prime 2}. In the Main Gyro Chamber in that game, there is a puzzle
is just to arrange all the 1s into the first row, all the 2s into
the second row, and so on.
+\b You can configure whether the orientation of tiles matters. If
+you ask for an orientable puzzle, each tile will have a yellow bar
+along the side that should be at the top, and a green bar along the
+side that should be at the bottom. To remind you of which way round
+things go, there will be coloured bars by the sides of the grid.
+Line up matching colours horizontally to complete the puzzle.
+
\C{rectangles} \i{Rectangles}