On the Homepage of The Game Master You could [but by 2016 no longer...] find this Variation:
Variation of the game for advanced players:
Section X is even better if a number of changes are made to the rules that increase the tactical factors and the level of difficulty and make the game last somewhat longer:
(1) The aim of the game is to get seven, instead of five, prisoners to freedom;
(2) Instead of three face-down piles three open piles are made, with the player always being able to choose in phase 1 from which pile of tiles he wishes to take a tile;
(3) Phases two and three can be changed around in each turn. This makes it possible, for example, to first move a number of prisoners, then to exchange or move a tile and then to move a number of prisoners again. Naturally, the rule that only one exchange, placing, moving or turning of tiles still applies to the tiles and a maximum of five steps is allowed for the prisoners with a maximum of two steps per prisoner.