Copyright (c) 1997 Patch Products

This game is played on a 7x7 square board, with the following setup:

SLIDE  - A stone may slide one cell in any orthogonal direction, and eventually push other stones.
To slide a stone, there must be access to it. For example, to slide a stone to the left, the space just to the right of the stone being moved, cannot have any stone.
KO rule - If a player pushes stones in one direction, the other player may not push these stones back in the opposite direction in his next move if
the full board position is repeated, but must wait one turn.
The player cannot push his own stones off the board.
When a player push off board, one stone, he may slide again.
GOAL - The player who push off seven red stones or all the enemy stones, wins

Ralf Gering notes: this rule [the KO rule] isn't perfect as there are full board repetitions after 4 moves. It would be best if the rule would simply be: It's not permitted to repeat a full board position during a game.

An example

Black started by sliding the two black stones at b1 and b2 north.

Winning the game

The marked Black stone moves a3-a2 and pushes the White stone to a1. Since White cannot push back to a2, he must move a1-b1 (pushing the black stone to c1), loosing on the next turn.

There is a computer demo that plays the game at Patch Products website. A variant is Kubatoo with the following rules:

The object of the game is to collect seven red neutral marbles by pushing them off the board.
  1. Each player takes turns pushing one of their marbles (Black or White) horizontally or vertically one space.
  2. A marble must have an empty space behind it to push it (off the board counts.)
  3. Marbles ahead of a pushed marble are also moved regardless of their color or how many.
  4. A marble is captured if it is pushed off the board. Captured enemy marbles are removed from the board. Captured neutral red marbles are placed in the capturing player's storage area.
  5. Players may not capture their own marbles.
  6. To win a player must collect seven red marbles. It is also possible to win by eliminating all of an opponent's moves.
  7. A player may not make a move that puts the board back to the position it was before the opponent's last move.