3 Rotate the grid squares so that they all join up into a single
4 connected network with no loops.
6 Left-click in a square to rotate it anticlockwise. Right-click to
7 rotate it clockwise. Middle-click, or shift-left-click if you have
8 no middle mouse button, to lock a square once you think it is
9 correct (so you don't accidentally rotate it again); do the same
10 again to unlock it if you change your mind.
12 Squares connected to the middle square are lit up. Aim to light up
13 every square in the grid (not just the endpoint blobs).
15 When this gets too easy, select a 'wrapping' variant from the Type
16 menu to enable grid lines to run off one edge of the playing area
17 and come back on the opposite edge!