Picross

This is another challenging puzzle game which is perfect for a handheld platform like the Lynx where you just want to kill some time while waiting somewhere and yet you want a little brain stimulus, too.

The concept is simple: you get a grid of empty boxes, and some numbers outside the grid indicating how many boxes are filled in that row or column. You must then deduce exactly which boxes are filled in based on this limited information. End result is a cute little picture.