Number Link at sizes up to around 10×10  may not necessarily be hugely challenging for everyone, but I bet you now that this puzzle certainly will be!  Despite being only 8×8 it is really very difficult indeed.  Or perhaps that’s just me – I’d love to hear that someone finds it easy, but I’m not expecting anyone to!

The rules of this puzzle are, however, very simple:

• Connect each pair of identical numbers with a single line
• Lines can travel horizontally or vertically between squares
• Only one line can enter any square (this means lines cannot cross or overlap in any way)
• Your lines may wrap around from one side of the puzzle to the other, so for example if you travel off the right-hand end of a row then your line will continue on in the left-most square of that row

There is a unique solution to this puzzle, and it uses every square.  However, the solution is unique even without the constraint that it uses every square.

If you’ve played toroidal sudoku then you’ll hopefully understand how the wrap around works – when you go off the top of a column you come back on the bottom, and similarly (as stated above) for rows.  If the basic rules of Number link itself confuse you, take a look back at a post a few days ago for an example.

And good luck – I think you’ll need it!