TOPPEN

バベルの塔 ("Tower of Babel"), also known as TOPPEN, is played with ten tiles — five black and five red — with each player taking one color. During set-up, the second player places the ten tiles face down randomly in a square grid so as to form a continuous shape of their choice. The tiles are flipped color-side up, then the game begins. Taking turns, players take one of their tiles and place it on top of a neighboring tile/stack. The following restrictions apply:

You can take only one tile, the topmost of a stack.
You cannot split the tiles into two separate groups.
You cannot move a tile to an empty space.

If you cannot make a legal move, you must pass until a legal move is available to you again. You cannot pass if a move is available.

The goal is to have your own tile at the top of the last pile remaining when the game ends.