sgt-puzzles/html/twiddle.html

Twiddle
<p>
Rotate square sections of the grid to arrange the squares into
numerical order starting from the top left.
<p>
In the basic game, you rotate a 2&times;2 square section. Left-click
in the centre of that section (i.e. on a corner point between four
squares) to rotate the whole section anticlockwise. Right-click to
rotate the section clockwise.
<p>
When you master the basic game, go to the Type menu to try it with
larger rotating groups (for a 3&times;3 group you must click in the
centre of a square to rotate the block around it). Or select the
'orientable' mode in which every square must end up the right way
round as well as in the right place. Or both!