Click an empty position to place your man.
A move consists of walking straight until you encounter a wall or your own footprints. In this case you can turn 90 degrees (left or right) to either side.

Your goal is to walk as many steps (make as many moves) as possible.
The number of your moves as well as the length of the longest known walk are shown at the top border.
You can edit the digits of this limit simply by clicking them (after you dropped your man). To get a win-message, however, the limit must be set to be greater than 9.

When SmartMoves is activated, you simply click the target position to move your man. Activate it via View/Options/Board/SmartMoves.

You win when you played the maximum amount of moves.
Solutions are attached (some supplied by Alfred Pfeiffer).

There are also ten randomized variants attached. In these variants, try to play as many moves as possible and then let the computer calculate the longest path (with 1 minute thinking time).