Squex

Squex is a 2-player abstract connection game, similar to Hex. The game is played on a 8x8 board of octagons and squares. The goal of each player is to connect their corresponding sides of the board with a continuous line of pieces.

How to play:

 On their turn, each player can place one octagonal piece on any free octagonal place on the board.
 If a piece is placed diagonally to a piece of the same color, a square of that color is placed to connect them (it is possible to place up to 4 squares by placing just one octagon).
 If a piece is placed diagonally to a piece of the same color and there is a square of the opponent's color in between them, the opponent's square is replaced by a square of the player's color. The opponent's octagons are no longer connected by the square that was there. This is called a "cut".
 Whenever a player performs a "cut", the opponent can then play two times in a row (it should be noted that if a player performs a "cut" on the first of two consecutive turns, they lose the second turn and it's the opponent's turn to play twice).
 A player only wins when they connect their respective sides of the board and it is impossible for the opponent to ever break that connection with a "cut". Usually after a player connects two sides there are still three of four more turns until the connection is "uncutable".

—description from the designer