Five Cells. Mark walls along the gridlines to divide the grid into pentominoes such that each number tells exactly how many walls are among the four sides of the cell containing the number. 10×10. Easy-ish or something.
Puzzle 9: Five Cells
This puzzle has symmetry, unusual for Five Cells. Mostly toying around with one trick used at least twice that I remember, plus another trick used also at least twice. Yay. Puzzle 10 is ready, but it will be posted when it strikes 00.00 on 6 August (Monday) my time, for a reason you’ll see…
Update (4-Aug-2012 20:32 UTC+7): Fixed a multiple solution issue.
Chaos at the Sky 